KS3 Physics — Recall & Retrieval

1.

What is the energy value of a food?

The energy value of a food is the amount of energy released when the food is used by the body.

2.

What unit is used to measure the energy value of food?

The energy value of food is measured in kilojoules (kJ).

3.

How can food labels be used to compare the energy values of different foods?

Food labels can be compared by looking at the energy value per 100 g or per serving.

4.

What does kJ stand for?

kJ stands for kilojoule.

5.

What does a higher energy value on a food label mean?

A higher energy value means the food provides more energy to the body.

6.

What is power?

Power is the rate at which energy is transferred.

7.

What unit is used to measure power?

Power is measured in watts (W).

8.

What does W stand for?

W stands for watt.

9.

What does kW stand for?

kW stands for kilowatt.

10.

How can the power ratings of two appliances be compared?

Compare the power ratings shown on the appliances.

11.

What does a higher power rating mean for an appliance?

A higher power rating means the appliance transfers energy more quickly.

12.

What is the difference between energy and power?

Energy is the amount of energy transferred, while power is how quickly energy is transferred.

13.

What units can be used to measure the amount of energy transferred?

Energy can be measured in joules (J) or kilowatt-hours (kWh).

14.

What does J stand for?

J stands for joule.

15.

What does kWh stand for?

kWh stands for kilowatt-hour.

16.

How can the amount of energy transferred by two appliances be compared?

Compare the amount of energy transferred by each appliance over the same period of time.

17.

What is a domestic fuel bill?

A domestic fuel bill shows the cost of energy used in a home.

18.

What information can be found on a domestic fuel bill?

A domestic fuel bill can show the amount of energy used, the cost per unit and the total cost.

19.

How does the amount of fuel used affect the cost of a fuel bill?

The more fuel used, the more energy is used and generally the higher the cost.

20.

What factors affect the cost of using a domestic fuel?

The cost depends on factors such as the amount of fuel used and the price per unit of fuel.

21.

What is a fuel?

A fuel is a substance that releases energy when it reacts, usually by burning.

22.

What is an energy resource?

An energy resource is a source from which useful energy can be obtained.

23.

What is a renewable energy resource?

A renewable energy resource is a resource that is naturally replaced and will not run out through normal use.

24.

What is a non-renewable energy resource?

A non-renewable energy resource is a resource that is used faster than it is replaced and can eventually run out.

25.

What are the main differences between renewable and non-renewable energy resources?

Renewable resources are naturally replaced, while non-renewable resources are limited and take a very long time to form.

Energy changes and transfers

1.

What is a simple machine?

A simple machine is a device that makes it easier to move or lift a load by changing the size or direction of a force.

2.

How can a simple machine produce a bigger force?

A simple machine can produce a bigger force by using a smaller force over a greater distance.

3.

What happens to the movement when a simple machine produces a bigger force?

When a simple machine produces a bigger force, the distance moved is smaller.

4.

What happens to the force when a simple machine produces a bigger movement?

When a simple machine produces a bigger movement, the force produced is smaller.

5.

What does it mean when the product of force and displacement is unchanged?

It means that the force and distance change in opposite ways, so the overall work done remains the same.

6.

What causes thermal energy to transfer between two objects?

A temperature difference causes thermal energy to transfer between objects.

7.

In which direction does thermal energy transfer between two objects at different temperatures?

Thermal energy transfers from the hotter object to the cooler object.

8.

What is thermal equilibrium?

Thermal equilibrium is reached when objects have the same temperature and there is no overall transfer of thermal energy between them.

9.

What happens to the temperature difference between two objects as they reach thermal equilibrium?

The temperature difference gets smaller until it reaches zero.

10.

What is conduction?

Conduction is the transfer of thermal energy through a substance from hotter areas to cooler areas.

11.

How does conduction transfer energy?

Conduction transfers energy through collisions and vibrations of particles.

12.

What is radiation?

Radiation is the transfer of energy by electromagnetic waves, such as infrared radiation.

13.

What is convection?

Convection is the transfer of thermal energy by the movement of a fluid, such as a liquid or gas.

14.

What is an insulator?

An insulator is a material that reduces the transfer of thermal energy.

15.

How do insulators reduce energy transfer?

Insulators reduce energy transfer because they are poor conductors of thermal energy.

16.

How is energy transferred when an object's motion changes?

Energy is transferred to or from an object's kinetic energy store when its motion changes.

17.

How is energy transferred when an object is dropped?

When an object is dropped, energy is transferred from its gravitational potential energy store to its kinetic energy store.

18.

How is energy transferred when an electrical circuit is completed?

When an electrical circuit is completed, energy is transferred electrically to the components.

19.

How is energy transferred when a spring is stretched?

When a spring is stretched, energy is transferred to its elastic potential energy store.

20.

How is energy transferred during the metabolism of food?

During the metabolism of food, energy stored in food is transferred to the body's energy stores and surroundings.

21.

How is energy transferred when a fuel burns?

When a fuel burns, energy stored in the fuel is transferred to the surroundings, mainly as thermal energy and light.

22.

What happens to the temperature of an object when it gains thermal energy?

The temperature of an object increases when it gains thermal energy.

23.

What happens to the temperature of an object when it loses thermal energy?

The temperature of an object decreases when it loses thermal energy.

24.

How does heating transfer energy from a hotter object to a cooler object?

Heating transfers thermal energy from a hotter object to a cooler object.

25.

Why does thermal energy transfer tend to reduce the temperature difference between objects?

Thermal energy transfer reduces the temperature difference because energy moves from the hotter object to the cooler object.

Changes in systems

1.

What is energy?

Energy is the ability to cause change or make things happen.

2.

What does it mean to say that energy can be measured?

Energy can be measured by measuring the amount of energy transferred or stored.

3.

What happens to the total amount of energy during a change?

The total amount of energy is conserved during a change; it is transferred between stores or to the surroundings.

4.

What happens to the energy of a moving object when it speeds up?

When a moving object speeds up, its kinetic energy increases.

5.

What happens to the energy of an object when its temperature increases?

When an object's temperature increases, its thermal energy increases.

6.

What happens to an object's energy when it is raised higher?

When an object is raised higher, its gravitational potential energy increases.

7.

What happens to the energy stored in a spring when it is stretched?

When a spring is stretched, energy is stored in its elastic potential energy store.

8.

What happens to energy stored in a fuel when the fuel burns?

When a fuel burns, energy stored in the fuel is transferred to other energy stores and the surroundings.

9.

What should be compared to describe the energy changes in a system?

To describe energy changes in a system, compare the energy stores before and after the change and how energy is transferred between them.

10.

What physical processes can cause energy to be transferred or changed?

Physical processes such as heating, cooling, movement, electrical transfer and changes of state can transfer or change energy.

Describing motion

1.

What is speed?

Speed is how fast an object moves.

2.

What is the equation for speed?

speed = distance ÷ time

3.

What unit is speed usually measured in?

Speed is usually measured in metres per second (m/s).

4.

What is distance?

Distance is the length of the path travelled by an object.

5.

What unit is distance usually measured in?

Distance is usually measured in metres (m).

6.

What is time?

Time is the duration of an event or movement.

7.

What unit is time usually measured in?

Time is usually measured in seconds (s).

8.

How is average speed calculated?

Average speed is calculated using total distance ÷ total time.

9.

A car travels 120 m in 10 s. What is its average speed?

12 m/s

10.

A cyclist travels at 8 m/s for 15 s. How far does the cyclist travel?

120 m

11.

What happens to average speed if the same distance is travelled in less time?

The average speed increases.

12.

What happens to average speed if more distance is travelled in the same time?

The average speed increases.

13.

What is a distance-time graph?

A distance-time graph shows how an object's distance changes with time.

14.

What does the gradient of a distance-time graph represent?

The gradient represents the object's speed.

15.

What does a horizontal line on a distance-time graph show?

A horizontal line shows that the object is stationary.

16.

What does a straight sloping line on a distance-time graph show?

A straight sloping line shows that the object is moving at a constant speed.

17.

What does a steeper line on a distance-time graph show?

A steeper line shows a greater speed.

18.

What does a curved line on a distance-time graph show?

A curved line shows that the object's speed is changing.

19.

How can a distance-time graph be used to describe a journey?

It can show when an object is moving, stationary, speeding up or slowing down.

20.

How can the speed of an object be found from a distance-time graph?

Calculate the gradient of the graph using change in distance ÷ change in time.

21.

What is meant by relative motion?

Relative motion describes the motion of one object compared with another object.

22.

Why can two moving vehicles appear to move relative to each other?

Two moving vehicles can appear to move relative to each other because each vehicle is moving compared with the other.

23.

How do two vehicles travelling in the same direction move relative to each other?

If they travel in the same direction at the same speed, they appear stationary relative to each other.

24.

How do two vehicles travelling in opposite directions move relative to each other?

If they travel in opposite directions, their relative speed is the sum of their speeds.

25.

Why do two vehicles travelling towards each other appear to approach each other faster?

Their speeds add together when they move towards each other, so their distance apart decreases more quickly.

Forces and their effects

1.

What is a force?

A force is a push or a pull.

2.

What can a force do to an object?

A force can change an object's speed, direction or shape.

3.

How do forces arise between two objects?

Forces arise from interactions between objects.

4.

What is a push?

A push is a force that moves an object away from the object applying the force.

5.

What is a pull?

A pull is a force that moves an object towards the object applying the force.

6.

What is a force arrow used to show?

A force arrow is used to show the size and direction of a force.

7.

What does the direction of a force arrow show?

The direction of a force arrow shows the direction in which the force acts.

8.

How can forces acting in one dimension be added together?

Forces acting in one dimension can be added together by considering their directions; forces in opposite directions are subtracted.

9.

What are balanced forces?

Balanced forces are forces that are equal in size and opposite in direction, giving a resultant force of zero.

10.

What are forces measured in?

Forces are measured in newtons (N).

11.

What happens when the forces acting on an object are balanced?

When forces are balanced, the object remains stationary or continues moving at a constant speed in a straight line.

12.

What happens when the forces acting on an object are unbalanced?

When forces are unbalanced, the object accelerates, decelerates or changes direction.

13.

What is a moment?

A moment is the turning effect of a force around a pivot.

14.

What is meant by the turning effect of a force?

The turning effect of a force is the tendency of a force to make an object rotate.

15.

What is a pivot?

A pivot is the point around which an object turns.

16.

How does the distance from a pivot affect the turning effect of a force?

A force has a greater turning effect when it acts further from the pivot.

17.

What is deformation?

Deformation is a change in the shape of an object.

18.

How can a force cause an object to deform?

A force can deform an object by stretching, squashing, bending or twisting it.

19.

What happens when an object is stretched?

When an object is stretched, it gets longer.

20.

What happens when an object is squashed?

When an object is squashed, it gets shorter or changes shape.

21.

What is friction?

Friction is a force that opposes motion between surfaces that are touching.

22.

How does friction affect moving objects?

Friction slows down moving objects and can produce thermal energy.

23.

What happens when an object pushes through air or water?

An object moving through air or water experiences a resistive force that opposes its motion.

24.

What is air resistance?

Air resistance is a force that opposes an object's motion through air.

25.

What is water resistance?

Water resistance is a force that opposes an object's motion through water.

Springs, energy and non-contact forces

1.

What unit is force measured in?

Force is measured in newtons (N).

2.

What is extension?

Extension is the increase in length of a spring when a force is applied.

3.

How is the extension of a spring calculated?

extension = stretched length − original length

4.

What is compression?

Compression is when an object is squashed so that its length decreases.

5.

What happens to the extension of a spring when the force increases?

The extension of a spring generally increases as the force increases, provided the limit of proportionality is not exceeded.

6.

How can the extension of a spring be measured?

Measure the spring's original length, then its length with the force applied, and subtract the original length from the new length.

7.

What is a force-extension relationship?

A force-extension relationship shows how the extension of a spring changes when the applied force changes.

8.

What does a straight-line force-extension relationship show?

A straight-line force-extension relationship shows that extension is directly proportional to force.

9.

What is Hooke's Law?

Hooke's Law states that the extension of a spring is proportional to the force applied, provided the limit of proportionality is not exceeded.

10.

What happens when a spring is stretched beyond its limit of proportionality?

Beyond the limit of proportionality, the spring's extension is no longer proportional to the force.

11.

What is work done?

Work done is the energy transferred when a force moves an object through a distance.

12.

What happens to energy when an object is deformed?

Energy is transferred to the object's elastic potential energy store when it is deformed.

13.

Where is energy stored when a spring is stretched?

Energy is stored in the spring's elastic potential energy store.

14.

What is a non-contact force?

A non-contact force is a force that acts without objects touching.

15.

What is gravity?

Gravity is a force of attraction between masses.

16.

How can gravity act between objects that are not touching?

Gravity can act between objects because masses attract each other even when they are not touching.

17.

How does gravity act on objects near Earth?

Near Earth, gravity pulls objects towards the centre of the Earth.

18.

How does gravity act between objects in space?

In space, gravity can cause objects to attract each other and move in orbits.

19.

What is a magnetic force?

A magnetic force is a non-contact force caused by magnets acting on other magnets or magnetic materials.

20.

What happens when two like magnetic poles are brought together?

Like magnetic poles repel each other.

21.

What happens when two unlike magnetic poles are brought together?

Unlike magnetic poles attract each other.

22.

What is static electricity?

Static electricity is the build-up of electric charge on an object.

23.

What happens when two objects have the same electric charge?

Objects with the same electric charge repel each other.

24.

What happens when two objects have opposite electric charges?

Objects with opposite electric charges attract each other.

25.

What are three types of non-contact force?

Three types of non-contact force are gravitational, magnetic and electrostatic forces.

Pressure in fluids

1.

What is atmospheric pressure?

Atmospheric pressure is the pressure caused by the weight of the air above a surface.

2.

What causes atmospheric pressure?

Atmospheric pressure is caused by the weight of the air in the atmosphere.

3.

Why does atmospheric pressure decrease as height increases?

Atmospheric pressure decreases with height because there is less air above you.

4.

What happens to the weight of air above you as height increases?

The weight of air above you decreases as height increases.

5.

How does the weight of air above you affect atmospheric pressure?

Less weight of air above you means less atmospheric pressure.

6.

What is pressure in a liquid?

Liquid pressure is the force exerted by a liquid on a surface.

7.

How does liquid pressure change with depth?

Liquid pressure increases as depth increases.

8.

Why does liquid pressure increase with depth?

Liquid pressure increases with depth because there is more liquid above, producing greater pressure.

9.

What is upthrust?

Upthrust is an upward force exerted by a fluid on an object.

10.

What causes upthrust on an object in a liquid?

Upthrust is caused by the pressure of the fluid acting on the object.

11.

How does upthrust affect whether an object floats or sinks?

Upthrust helps determine whether an object floats or sinks.

12.

What happens when upthrust is greater than the weight of an object?

The object moves upwards.

13.

What happens when the weight of an object is greater than its upthrust?

The object moves downwards and may sink.

14.

What happens when upthrust equals the weight of an object?

The object is in equilibrium and can remain at rest.

15.

What is pressure?

Pressure is the force acting on a given area.

16.

What is the equation for pressure?

Pressure = force ÷ area.

17.

What unit is pressure measured in?

Pressure is measured in pascals (Pa).

18.

What unit is force measured in when calculating pressure?

Force is measured in newtons (N).

19.

What unit is area measured in when calculating pressure?

Area is measured in square metres (m²).

20.

What happens to pressure when the force increases but the area stays the same?

The pressure increases.

21.

What happens to pressure when the area increases but the force stays the same?

The pressure decreases.

22.

Why does a sharp object produce a greater pressure than a blunt object?

A sharp object has a smaller contact area, so the same force produces greater pressure.

23.

What does it mean for a force to act normally to a surface?

The force acts at right angles to the surface.

24.

How does the contact area affect the pressure produced by a force?

A smaller contact area produces greater pressure, while a larger contact area produces lower pressure.

25.

How can pressure be calculated from force and area?

Divide the force by the area: pressure = force ÷ area.

Balanced forces

1.

What are opposing forces?

Opposing forces are forces acting in opposite directions.

2.

What is equilibrium?

Equilibrium is when the forces acting on an object are balanced.

3.

What happens when opposing forces are balanced?

The object remains at rest or continues moving at a constant speed in a straight line.

4.

What force acts downwards on an object because of gravity?

Weight is the downward force caused by gravity.

5.

How can a stretched spring support an object?

A stretched spring provides an upward force that can balance the object's weight.

6.

How can a compressed surface support an object?

A compressed surface provides an upward support force.

7.

What happens when the upward support force equals the object's weight?

The object is in equilibrium.

8.

Why does an object remain in equilibrium when its weight is balanced?

The upward support force balances the downward weight.

9.

What happens to an object when its weight is greater than the upward support force?

The object accelerates downwards.

10.

What happens to an object when the upward support force is greater than its weight?

The object accelerates upwards.

Forces and motion

1.

What can a force do to an object that is at rest?

A force can make an object start moving.

2.

What can a force do to an object's speed?

A force can make an object speed up or slow down.

3.

What can a force do to an object's direction of motion?

A force can change the direction in which an object moves.

4.

What happens when a force acts in the same direction as an object's motion?

The object tends to speed up.

5.

What happens when a force acts opposite to an object's motion?

The object tends to slow down.

6.

What happens when a force acts at an angle to an object's motion?

The object's speed and/or direction of motion can change.

7.

How does the size of a force affect its effect on an object's motion?

A larger force generally produces a greater change in motion.

8.

How does the direction of a force affect an object's motion?

The direction of the force determines the direction of the change in motion.

9.

Why is a force needed to make an object start moving?

A force is needed to change the object's state from rest to motion.

10.

Why is a force needed to make an object stop or change its motion?

A force is needed to change the object's motion, such as stopping it or changing its direction.

Observed waves

1.

What is a water wave?

A water wave is a disturbance that transfers energy through water.

2.

How do water waves travel through water?

Water waves transfer energy through the water while the water particles mainly move up and down.

3.

What type of wave motion do water waves have?

Water waves have transverse wave motion.

4.

What is a transverse wave?

A transverse wave is a wave where the particles vibrate at right angles to the direction the wave travels.

5.

What happens when a water wave is reflected?

The wave changes direction when it bounces off a surface.

6.

What happens when two waves meet?

The waves combine when they meet.

7.

What is superposition?

Superposition is when two or more waves overlap and their effects combine.

8.

What happens when two waves add together?

The waves produce a larger resultant wave.

9.

What happens when two waves cancel each other?

The waves produce a smaller resultant wave and may cancel completely.

10.

How can reflection and superposition change the appearance of water waves?

Reflection can change the direction of waves, while superposition can make waves larger or smaller.

Sound waves

1.

What is frequency?

Frequency is the number of waves or vibrations passing a point each second.

2.

What unit is frequency measured in?

Frequency is measured in hertz (Hz).

3.

What does a high-frequency sound have compared with a low-frequency sound?

A high-frequency sound has a higher pitch.

4.

What is an echo?

An echo is a reflected sound heard again after the original sound.

5.

How is an echo produced?

An echo is produced when sound waves reflect from a surface and return to the listener.

6.

What happens when sound is reflected?

Sound waves bounce back from a surface.

7.

What happens when sound is absorbed?

Sound energy is absorbed by the material.

8.

Why does sound need a medium to travel through?

Sound needs a medium because its vibrations are passed from particle to particle.

9.

What is a medium?

A medium is a substance through which a wave can travel.

10.

Can sound travel through a vacuum?

No. Sound cannot travel through a vacuum.

11.

How does the speed of sound in air compare with its speed in water?

Sound travels faster in water than in air.

12.

How does the speed of sound in solids compare with its speed in air?

Sound travels faster in solids than in air.

13.

What produces sound?

Sound is produced by vibrating objects.

14.

How does a loudspeaker produce sound?

A loudspeaker's diaphragm vibrates, producing sound waves.

15.

How does a microphone detect sound?

A microphone detects sound vibrations and converts them into an electrical signal.

16.

What happens to a microphone diaphragm when sound reaches it?

The microphone diaphragm vibrates.

17.

What part of the ear detects sound vibrations?

The eardrum detects sound vibrations.

18.

What type of wave is sound?

Sound is a longitudinal wave.

19.

What is a longitudinal wave?

A longitudinal wave is a wave where particles vibrate parallel to the direction the wave travels.

20.

How do particles move in a longitudinal wave?

Particles move backwards and forwards parallel to the direction of wave travel.

21.

What is the auditory range of humans?

The human auditory range is approximately 20 Hz to 20,000 Hz (20 kHz).

22.

How can the auditory range of animals differ from that of humans?

Different animals have different auditory ranges, with some able to hear higher or lower frequencies than humans.

23.

Why can some animals hear sounds that humans cannot hear?

Their ears and hearing systems are adapted to detect different frequencies.

24.

What happens to sound when it reaches a surface that absorbs it?

The sound energy is absorbed, so less sound is reflected.

25.

How can reflected sound be used to produce an echo?

Sound waves reflect from a surface and return to the listener, producing an echo.

Energy and waves

1.

What do pressure waves transfer?

Pressure waves transfer energy.

2.

What is ultrasound?

Ultrasound is sound with a frequency above the upper limit of human hearing.

3.

How can ultrasound be used for cleaning?

Ultrasound can be used to clean objects by producing vibrations that help remove dirt.

4.

How can ultrasound be used in physiotherapy?

Ultrasound can be used in physiotherapy to transfer energy into tissues and help treat injuries.

5.

How can waves transfer information?

Waves can transfer information by carrying signals from one place to another.

6.

How can a microphone convert sound into an electrical signal?

A microphone converts sound vibrations into an electrical signal.

7.

What happens when a sound wave reaches a microphone?

The sound wave makes the microphone's diaphragm vibrate.

8.

What part of a microphone responds to sound vibrations?

The diaphragm responds to sound vibrations.

9.

Why are pressure waves useful for transferring energy?

Pressure waves are useful for transferring energy because they carry energy from one place to another.

10.

Why are waves useful for transferring information?

Waves are useful for transferring information because they can carry signals from one place to another.

Light waves and reflection

1.

What is a light wave?

A light wave is a wave that transfers energy and allows us to see.

2.

How are light waves similar to waves in matter?

Light waves can transfer energy and can be reflected, absorbed or transmitted.

3.

How are light waves different from waves in matter?

Light waves do not need a material medium to travel through, unlike waves in matter.

4.

Can light waves travel through a vacuum?

Yes, light waves can travel through a vacuum.

5.

What is a vacuum?

A vacuum is a region containing no matter.

6.

What is the speed of light in a vacuum?

The speed of light in a vacuum is about 300,000,000 m/s.

7.

Why can light travel through empty space?

Light can travel through empty space because it does not need particles to transfer its energy.

8.

What happens when light is absorbed by a material?

The material absorbs the light energy.

9.

What is absorption of light?

Absorption is when a material takes in light energy.

10.

What is diffuse scattering of light?

Diffuse scattering is when light is scattered in many different directions from a rough surface.

11.

What happens to light during diffuse scattering?

The light is reflected in many different directions.

12.

What is specular reflection?

Specular reflection is the reflection of light from a smooth surface in a regular direction.

13.

What happens to light during specular reflection?

Light is reflected in a regular direction.

14.

How is diffuse scattering different from specular reflection?

Diffuse scattering sends light in many directions, while specular reflection sends light in a regular direction.

15.

What type of surface produces specular reflection?

A smooth, shiny surface produces specular reflection.

16.

What type of surface produces diffuse scattering?

A rough surface produces diffuse scattering.

17.

What happens to light when it reaches a material that does not transmit it?

The light is absorbed or reflected rather than transmitted through the material.

18.

What happens to the energy of light when it is absorbed?

The light energy is transferred to the material, often increasing its thermal energy.

19.

How does the behaviour of light change when it reaches different materials?

Light may be absorbed, transmitted, reflected or scattered depending on the material.

20.

What is meant by the transmission of light?

Transmission is the passing of light through a material.

21.

What happens when light is transmitted through a material?

The light passes through the material.

22.

What happens when light is reflected from a surface?

The light changes direction as it bounces off the surface.

23.

What happens when light is scattered from a surface?

The light is reflected in many different directions.

24.

How can a surface affect the way light is reflected or scattered?

Smooth surfaces tend to produce specular reflection, while rough surfaces tend to produce diffuse scattering.

25.

What are the three ways light can interact with a material: absorption, transmission and reflection?

Light can be absorbed, transmitted or reflected by a material.

Light rays, lenses and the eye

1.

What is a ray model of light?

The ray model represents light as straight lines called rays.

2.

What do arrows on light rays show?

Arrows on light rays show the direction in which the light travels.

3.

How can the ray model be used to show how light travels?

The ray model can show the path of light using straight lines and arrows.

4.

How is an image formed in a plane mirror?

A plane mirror forms an image by reflecting light from the object into the observer's eyes.

5.

What happens to light when it reaches a mirror?

Light is reflected from the mirror.

6.

What is a pinhole camera?

A pinhole camera is a simple camera with a small hole that allows light to enter.

7.

How does a pinhole camera form an image?

Light travels in straight lines through the pinhole and forms an image on the opposite side.

8.

Why is the image formed by a pinhole camera upside down?

The image is upside down because light rays from the top and bottom of the object cross at the pinhole.

9.

What is refraction?

Refraction is the change in direction of light when it passes from one material into another.

10.

What happens to a light ray when it passes from one material into another?

The light ray changes direction and may change speed.

11.

Why does light change direction when it is refracted?

Light changes direction because its speed changes when it enters a different material.

12.

What is a convex lens?

A convex lens is a lens that is thicker in the middle than at the edges.

13.

What happens to light rays passing through a convex lens?

A convex lens bends light rays towards each other.

14.

What does it mean when a convex lens focuses light?

Focusing light means bringing light rays together at a point.

15.

What is the focal point of a convex lens?

The focal point is the point where parallel light rays meet after passing through a convex lens.

16.

How can a ray diagram show the focusing of light by a convex lens?

A ray diagram can show parallel rays bending towards each other and meeting at the focal point.

17.

What is the main function of the human eye?

The main function of the human eye is to detect light and form an image.

18.

What is the function of the cornea?

The cornea helps focus light as it enters the eye.

19.

What is the function of the iris?

The iris controls the size of the pupil.

20.

What is the function of the pupil?

The pupil is the opening through which light enters the eye.

21.

What is the function of the lens in the eye?

The lens focuses light onto the retina.

22.

What is the function of the retina?

The retina detects light and contains light-sensitive cells.

23.

What is the function of the optic nerve?

The optic nerve carries signals from the retina to the brain.

24.

How does the eye form an image of an object?

The eye forms an image by focusing light onto the retina.

25.

How does the eye detect light?

The eye detects light using light-sensitive cells in the retina.

Light, energy and colour

1.

How does light transfer energy from a source to an absorber?

Light transfers energy from a source to an absorber.

2.

What is a source of light?

A source of light is an object that produces or emits light.

3.

What is an absorber of light?

An absorber of light is a material that takes in light energy.

4.

What chemical effects can light cause?

Light can cause chemical changes, such as photosynthesis.

5.

What electrical effects can light cause?

Light can cause electrical effects, such as producing an electrical signal in a light-sensitive device.

6.

What is a photosensitive material?

A photosensitive material is a material that responds to light.

7.

Where is photosensitive material found in the human eye?

Photosensitive material is found in the retina of the eye.

8.

What is the role of photosensitive material in the retina?

Photosensitive material in the retina detects light and helps produce signals sent to the brain.

9.

How do cameras use photosensitive materials?

Cameras use photosensitive materials to detect and record light.

10.

What is meant by the colour of light?

The colour of light depends on its frequency.

11.

What is frequency?

Frequency is the number of waves passing a point each second.

12.

How are different colours of light related to frequency?

Different colours of light have different frequencies.

13.

What is white light?

White light is light containing a mixture of different colours.

14.

What colours make up white light?

White light contains the colours of the visible spectrum: red, orange, yellow, green, blue, indigo and violet.

15.

What happens when white light passes through a prism?

A prism separates white light into its different colours.

16.

Why does a prism separate white light into different colours?

Different colours of light are refracted by different amounts as they pass through the prism.

17.

What is a light filter?

A light filter is a material that allows some colours of light through and absorbs others.

18.

How does a coloured filter affect white light?

A coloured filter transmits its own colour and absorbs many of the other colours.

19.

What happens when white light falls on a black object?

Much of the white light is absorbed by the black object.

20.

Why does a black object appear black?

A black object appears black because it absorbs most of the visible light that falls on it.

21.

Why does a red object appear red?

A red object appears red because it diffusely reflects red light and absorbs much of the other visible light.

22.

Why does a white object appear white?

A white object appears white because it diffusely reflects most of the visible light.

23.

What happens when light is absorbed by a coloured object?

The light energy is transferred to the object.

24.

What happens when light is diffusely reflected from a coloured object?

The reflected light travels away from the object in many directions.

25.

Why does an object appear to have a particular colour?

An object appears a particular colour because of the colours of light it reflects into our eyes.

Current electricity

1.

What is electric current?

Electric current is the flow of electric charge.

2.

What is the unit of electric current?

Electric current is measured in amperes (A).

3.

What does an ammeter measure?

An ammeter measures electric current.

4.

What is meant by the flow of charge?

The flow of charge means electric charge moving through a circuit.

5.

What is a series circuit?

A series circuit has components connected in a single loop.

6.

What is a parallel circuit?

A parallel circuit has components connected in separate branches.

7.

How does current behave in a series circuit?

The current is the same at all points in a series circuit.

8.

What happens to current where branches meet in a parallel circuit?

The current splits between the branches and recombines where the branches meet.

9.

What is potential difference?

Potential difference is the difference in electrical energy per unit charge between two points.

10.

What unit is potential difference measured in?

Potential difference is measured in volts (V).

11.

What does a voltmeter measure?

A voltmeter measures potential difference.

12.

What does a battery provide in an electrical circuit?

A battery provides a potential difference that pushes charge around a circuit.

13.

What does a bulb rating tell you?

A bulb rating tells you the voltage and/or power the bulb is designed to operate at.

14.

What is resistance?

Resistance is how much a component opposes the flow of electric current.

15.

What unit is resistance measured in?

Resistance is measured in ohms (Ω).

16.

What is the relationship between potential difference, current and resistance?

Potential difference, current and resistance are related by V = I × R.

17.

How can resistance be calculated from potential difference and current?

Resistance can be calculated using R = V ÷ I.

18.

What is a conductor?

A conductor is a material that allows electric current to flow easily.

19.

What is an insulator?

An insulator is a material that does not allow electric current to flow easily.

20.

How does resistance differ between conducting and insulating components?

Conductors have low resistance, while insulators have high resistance.

21.

Why does an insulator have a high resistance?

An insulator has high resistance because it strongly opposes the flow of charge.

22.

Why does a conductor have a low resistance?

A conductor has low resistance because charge can flow through it easily.

23.

How does current behave when a parallel circuit splits into branches?

The current divides between the different branches of a parallel circuit.

24.

What happens to the total current when current from branches meet?

The branch currents add together to give the total current.

25.

Why must a complete circuit be present for current to flow?

A complete circuit provides a continuous path for charge to flow.

Static electricity

1.

What is static electricity?

Static electricity is a build-up of electric charge on an object.

2.

What happens when two objects are rubbed together?

Rubbing two objects together can transfer electrons from one object to the other.

3.

Which particles are transferred when objects are rubbed together?

Electrons are transferred when objects are rubbed together.

4.

How can an object become negatively charged?

An object becomes negatively charged when it gains electrons.

5.

How can an object become positively charged?

An object becomes positively charged when it loses electrons.

6.

What happens when two objects have the same type of charge?

Objects with the same type of charge repel each other.

7.

What happens when two objects have opposite charges?

Objects with opposite charges attract each other.

8.

How does the force between charged objects depend on their charges?

The force between charged objects depends on the size of their charges and the distance between them.

9.

What is an electric field?

An electric field is a region where an electric charge experiences a force.

10.

How can an electric field exert a force on an object without direct contact?

An electric field can exert a force on a charged object without the objects touching.

Magnetism

1.

What is a magnetic pole?

A magnetic pole is a region of a magnet where the magnetic force is strongest.

2.

What are the two types of magnetic pole?

The two types of magnetic pole are north and south.

3.

What happens when two north poles are brought together?

Two north poles repel each other.

4.

What happens when two south poles are brought together?

Two south poles repel each other.

5.

What happens when a north pole and a south pole are brought together?

A north pole and a south pole attract each other.

6.

What is a magnetic field?

A magnetic field is the region around a magnet where magnetic forces act.

7.

How can a magnetic field be investigated using a compass?

A compass can be moved around a magnet to show the direction of the magnetic field at different points.

8.

What do magnetic field lines represent?

Magnetic field lines show the shape and direction of a magnetic field.

9.

What does the direction of magnetic field lines show?

The direction of magnetic field lines shows the direction of the force on a north pole.

10.

How does Earth produce a magnetic field?

Earth produces a magnetic field because of processes involving moving molten material in its outer core.

11.

How can a compass help with navigation?

A compass can help with navigation because its needle aligns with Earth's magnetic field.

12.

Why does a compass point in a particular direction?

A compass points in a particular direction because its magnetic needle aligns with Earth's magnetic field.

13.

What happens around a wire when an electric current flows through it?

A magnetic field is produced around the wire.

14.

What is an electromagnet?

An electromagnet is a magnet produced by an electric current.

15.

How can an electromagnet be made stronger?

An electromagnet can be made stronger by increasing the current, adding more coils, or using an iron core.

16.

What happens to an electromagnet when the current is switched off?

The magnetic field disappears or becomes much weaker when the current is switched off.

17.

What is a D.C. motor?

A D.C. motor is a device that uses electrical energy to produce rotational movement.

18.

What is the basic principle of a D.C. motor?

A D.C. motor works because a current-carrying wire in a magnetic field experiences a force.

19.

How does a magnetic field interact with a current-carrying wire?

A magnetic field exerts a force on a current-carrying wire.

20.

How can electricity produce movement in a motor?

The force on current-carrying wires in a magnetic field can make a motor rotate.

21.

Why are electromagnets useful?

Electromagnets are useful because they can be switched on and off and their strength can be changed.

22.

How are electromagnets different from permanent magnets?

An electromagnet needs an electric current, so it can be switched on and off; a permanent magnet remains magnetic without a current.

23.

How can a compass be used to detect a magnetic field?

A compass can show a magnetic field because its needle turns to align with the field.

24.

What happens to the magnetic field around a wire when the current changes?

Increasing the current makes the magnetic field stronger; reversing the current reverses the field direction.

25.

How are electricity and magnetism linked in an electromagnet?

An electric current produces a magnetic field, allowing electricity to be used to create an electromagnet.

Physical changes

1.

What is meant by conservation of material?

Conservation of material means that material is not created or destroyed during a physical change.

2.

What happens to the mass of a substance when it melts?

The mass stays the same when a substance melts, provided no material is lost.

3.

What happens to the mass of a substance when it freezes?

The mass stays the same when a substance freezes.

4.

What happens to the mass of a substance when it evaporates?

The mass stays the same when a substance evaporates if the vapour is not lost.

5.

What happens to the mass of a substance when it condenses?

The mass stays the same when a substance condenses.

6.

What happens to the mass of a substance when it dissolves?

The mass stays the same when a substance dissolves.

7.

What does it mean for a physical change to be reversible?

A reversible physical change can be changed back to the original substance or state.

8.

Why can melting and freezing be reversed?

Melting can be reversed by freezing, and freezing can be reversed by melting.

9.

Why can evaporation and condensation be reversed?

Evaporation can be reversed by condensation.

10.

What is sublimation?

Sublimation is when a solid changes directly into a gas without becoming a liquid.

11.

What happens during condensation?

During condensation, a gas changes into a liquid.

12.

What happens during evaporation?

During evaporation, particles escape from the surface of a liquid and become a gas.

13.

What happens during dissolving?

During dissolving, particles of a substance spread among the particles of the solvent.

14.

What is density?

Density is the mass of a substance per unit volume.

15.

How does the density of a solid generally compare with the density of a liquid?

A solid generally has a greater density than its liquid.

16.

How does the density of a liquid generally compare with the density of a gas?

A liquid generally has a greater density than a gas.

17.

How are the particles arranged in a solid?

The particles in a solid are closely packed in fixed positions.

18.

How are the particles arranged in a liquid?

The particles in a liquid are close together but can move past each other.

19.

How are the particles arranged in a gas?

The particles in a gas are far apart and move freely.

20.

What is Brownian motion?

Brownian motion is the random movement of particles caused by collisions with other particles.

21.

What causes Brownian motion in gases?

Brownian motion in gases is caused by collisions with fast-moving gas particles.

22.

What is diffusion?

Diffusion is the spreading out of particles from an area of higher concentration to an area of lower concentration.

23.

What causes diffusion in liquids and gases?

Diffusion is caused by the random movement of particles.

24.

How does a difference in concentration cause diffusion?

Particles diffuse from a region of higher concentration to a region of lower concentration until they become more evenly spread.

25.

What is the difference between a physical change and a chemical change?

A physical change does not produce a new substance, while a chemical change produces one or more new substances.

Particle model

1.

How are particles arranged in a solid?

Solid particles are closely packed and arranged in fixed positions.

2.

How are particles arranged in a liquid?

Liquid particles are close together but can move past each other.

3.

How are particles arranged in a gas?

Gas particles are far apart and move freely in all directions.

4.

How does the movement of particles differ between solids, liquids and gases?

Solid particles vibrate in fixed positions, liquid particles move past each other, and gas particles move freely.

5.

How does the spacing between particles differ in solids, liquids and gases?

Particles are closest together in solids, further apart in liquids, and very far apart in gases.

6.

How can the particle model explain changes of state?

Changes of state occur when particles gain or lose energy and change their movement and arrangement.

7.

How can the particle model explain why solids keep their shape?

Solid particles are held closely together and only vibrate around fixed positions.

8.

How can the particle model explain why liquids can flow and change shape?

Liquid particles can move past each other, allowing the liquid to flow.

9.

Why is ice less dense than liquid water?

Ice is less dense than liquid water because its particles form a more open structure when it freezes.

10.

What are atoms and molecules?

Atoms are single particles that make up elements, while molecules are groups of two or more atoms joined together.

Energy in matter

1.

What happens to the movement of particles when a substance is heated?

Particles move faster when a substance is heated.

2.

What happens to the spacing between particles when a substance is heated?

Particles generally become further apart when a substance is heated.

3.

What happens to the movement of particles when a substance is cooled?

Particles move more slowly when a substance is cooled.

4.

What happens to the spacing between particles when a substance is cooled?

Particles generally become closer together when a substance is cooled.

5.

What is internal energy?

Internal energy is the total energy stored inside a material due to its particles.

6.

Where is internal energy stored in a material?

Internal energy is stored in the movement and interactions of the particles.

7.

How does increasing temperature affect the internal energy of a material?

Increasing temperature increases the internal energy of a material.

8.

How does decreasing temperature affect the internal energy of a material?

Decreasing temperature decreases the internal energy of a material.

9.

How are particle movement and internal energy linked?

Faster-moving particles have greater kinetic energy, contributing to greater internal energy.

10.

How can heating a material change its internal energy?

Heating transfers energy to the particles, increasing the material's internal energy.

1.

What is gravity?

Gravity is a force of attraction between objects with mass.

2.

What is weight?

Weight is the force acting on an object due to gravity.

3.

An object has a mass of 6 kg on Earth. What is its weight? Use g = 10 N/kg.

Weight = mass × gravitational field strength = 6 × 10 = 60 N.

4.

What is the unit of weight?

Weight is measured in newtons (N).

5.

What is the unit of mass?

Mass is measured in kilograms (kg).

6.

What is the unit of gravitational field strength?

Gravitational field strength is measured in newtons per kilogram (N/kg).

7.

What is the gravitational field strength on Earth?

The gravitational field strength on Earth is approximately 10 N/kg.

8.

Why is an object's weight different on different planets?

An object's weight depends on the gravitational field strength, which is different on different planets.

9.

What is the gravitational force between the Earth and Moon?

The Earth and Moon attract each other through gravity.

10.

What is the gravitational force between the Earth and Sun?

The Earth and Sun attract each other through gravity.

11.

What is the Sun?

The Sun is a star at the centre of our Solar System.

12.

What is a star?

A star is a very large, hot ball of gas that gives out light and other radiation.

13.

How does the Sun compare with other stars?

The Sun is a fairly typical star, although stars vary in size, temperature and brightness.

14.

What is the Milky Way?

The Milky Way is the galaxy that contains our Solar System.

15.

What is a galaxy?

A galaxy is a huge collection of stars, gas and dust held together by gravity.

16.

What is another galaxy?

Another galaxy is a separate huge collection of stars, gas and dust outside our own galaxy.

17.

What causes the seasons on Earth?

The seasons are caused by the tilt of Earth's axis as Earth orbits the Sun.

18.

How is the Earth's tilt linked to the seasons?

Earth's tilted axis means different parts of Earth receive different amounts of sunlight during the year.

19.

Why is the length of daylight different at different times of the year?

Day length changes because the tilt of Earth's axis changes how long different parts of Earth are facing towards the Sun.

20.

Why can day length differ between the Northern and Southern Hemispheres?

The Northern and Southern Hemispheres are tilted towards the Sun at different times of the year.

21.

What happens to day length during summer in the Northern Hemisphere?

Daylight hours are longer during summer in the Northern Hemisphere.

22.

What happens to day length during winter in the Northern Hemisphere?

Daylight hours are shorter during winter in the Northern Hemisphere.

23.

What is a light year?

A light year is the distance light travels in one year.

24.

What does a light year measure?

A light year measures distance, not time.

25.

Why is a light year useful for describing distances in space?

A light year is useful because distances between stars and galaxies are extremely large.

Physics

Energy