Newton's laws of motion

Car X and car Y have engines that produce the same maximum forward force.

The cars are the same shape, but car X has a greater mass than car Y.

How does the maximum acceleration of car X and car Y compare?

Tick (✓) one box.

Car Y has a mass of 900 kg.

Calculate the resultant force on car Y.

Use the equation:

resultant force = mass × acceleration

A car moves at a constant speed on a level road.

Figure 4 shows the horizontal forces on the car.

The driver makes the car accelerate until the car reaches its maximum speed.

Explain how the horizontal forces on the car change as the car accelerates to its maximum speed.

To pass a driving test, drivers need to understand the difference between thinking distance and braking distance.

Complete the sentence.

Choose the answer from the box.

Complete the sentence.

Choose the answer from the box.

The braking distance is the distance travelled by the car under the braking

Figure 5 shows how speed affects the thinking distance and braking distance of a car.

The car is moving at a speed of 100 km/h.

Calculate the stopping distance of the car.

Use Figure 5.

Which two of the following would increase the stopping distance of a car?

Tick (✓) two boxes.

A car manufacturer makes two cars, X and Y.

The cars are identical, apart from their mass.

Car X has a greater mass than car Y.

How does the maximum acceleration of car X compare with the maximum acceleration of car Y ?

Cars have air bags that inflate to protect the driver if the car stops very suddenly.

Explain how air bags reduce the chance of injury to the driver.

Car X has a mass of 1400 kg and is travelling at 18 m/s.

The driver applies the brakes.

The car has a constant deceleration and comes to a stop in a distance of 24 m.

Calculate the resultant force on the car.

Use the Physics Equations Sheet.

Explain why braking causes an increase in the temperature of the brakes.

The driver of a car applies the brakes so the car has a large deceleration.

Give two possible risks of a large deceleration.

A student investigated how changing the mass of a trolley affects the acceleration of the trolley.

Figure 5 shows some of the equipment used.

The trolley in Figure 5 is not moving.

Which force prevents the trolley from moving?

Tick (✓) one box.

The force pulling on the trolley was increased so that the trolley accelerated.

The force was then kept constant and different masses were put on the trolley.

For each different mass the acceleration of the trolley was measured.

Draw one line from each variable to the correct quantity.

For one of the masses put on the trolley, the student recorded three values of acceleration.

Calculate the mean acceleration of the trolley.

Figure 6 shows some of the results.

Describe the relationship shown in Figure 6.

When the total mass of the trolley was 1.5 kg, the acceleration of the trolley

Calculate the resultant force acting on the trolley.

Use the equation:

resultant force = mass × acceleration

A student investigated how the acceleration of a trolley varies with the resultant force on the trolley.

Figure 10 shows some of the equipment used.

Figure 10 shows the force F which acts through the string.

What name is given to force F ?

Give one variable that should have been a control variable in this investigation.

The student held the trolley stationary and then released it.

The trolley moved along the runway with a constant acceleration.

The student recorded the time taken for the trolley to travel a measured distance along the runway.

Describe how the acceleration of the trolley can be calculated using the time taken and distance travelled by the trolley.

For one set of results, the force acting through the string was 2.0 N.

The student released the trolley three times and determined the following values for acceleration:

Calculate the uncertainty in the values of acceleration.

The runway was then raised at one end.

The force acting through the string remained the same.

Figure 11 shows this.

Explain how the acceleration was affected by raising the end of the runway.

Figure 12 shows a velocity–time graph for a train travelling between two stations.

Determine the distance travelled by the train in the first 600 s of the journey.

Explain what happens to the braking force as the train decelerates.

Use information from Figure 12.

Determine the maximum deceleration of the train.

Another train travels at a speed of 60 m/s.

A constant braking force of 270 000 N causes the train to decelerate and stop.

mass of train = 240 000 kg

Calculate the distance travelled while the braking force is applied.

Use the Physics Equations Sheet.

It is illegal for train drivers to drink alcohol before driving a train.

Explain how drinking alcohol would affect the stopping distance of a train.

Figure 25 shows the route an aeroplane takes as it travels from an airport terminal to the runway. Figure 25 has been drawn to scale.

Determine the magnitude of the aeroplane’s displacement from the start point to the finish point on Figure 25.

Figure 26 shows the direction of the horizontal forces acting on the aeroplane as it moves in a straight line towards the runway.

Determine the magnitude of the resultant horizontal force on the aeroplane.

Describe the motion of the aeroplane as it moves towards the runway.

Air resistance and friction are contact forces. Give one other example of a contact force.

The aeroplane stops for a short time and then accelerates along the runway. Figure 27 shows a distance–time sketch-graph for this stage of the journey.

Draw the velocity–time sketch-graph for this stage of the journey on Figure 28.

The aeroplane takes off from the runway, so its height above the ground increases. Figure 29 shows how atmospheric pressure varies with the height of the aeroplane above the ground.

Estimate the atmospheric pressure when the height of the aeroplane above the ground is 10 km.

What happens to the air surrounding the aeroplane as the height of the aeroplane above the ground increases? Tick (✓) one box.

Figure 3 shows the route an aeroplane takes as it travels from an airport terminal to the runway. Figure 3 has been drawn to scale.

Determine the magnitude of the aeroplane’s displacement from the start point to the finish point on Figure 3.

Figure 4 shows the direction of the horizontal forces acting on the aeroplane as it moves in a straight line towards the runway.

Determine the magnitude of the resultant horizontal force on the aeroplane.

Describe the motion of the aeroplane as it moves towards the runway.

Air resistance and friction are contact forces. Give one other example of a contact force.

The aeroplane stops for a short time and then accelerates along the runway. Figure 5 shows a distance–time sketch-graph for this stage of the journey.

Draw the velocity–time sketch-graph for this stage of the journey on Figure 6.

The aeroplane takes off from the runway, so its height above the ground increases. Figure 7 shows how atmospheric pressure varies with the height of the aeroplane above the ground.

Estimate the atmospheric pressure when the height of the aeroplane above the ground is 10 km.

What happens to the air surrounding the aeroplane as the height of the aeroplane above the ground increases? Tick (✓) one box.

Figure 3 shows a cyclist on a bicycle. The cyclist is moving at a constant velocity. Arrows A and B represent the horizontal forces acting on the bicycle and cyclist.

What is force A ? Tick (✓) one box.

What is force B ? Tick (✓) one box.

What is the relationship between force A and force B when the cyclist travels at a constant velocity? Tick (✓) one box.

The cyclist applies a force of 150 N to one of the bicycle pedals. Figure 4 shows the distance between the force applied and the pivot.

Calculate the moment about the pivot caused by the force applied to the pedal in Figure 4. Use the equation: moment of a force = force × distance

Figure 5 shows how the pedal is connected to the back wheel of the bicycle.

Complete the sentence. Choose the answer from the box.

axle chain cog

The force from the cyclist pushing down on the pedal is transmitted to the back wheel

Figure 6 shows how the velocity of the cyclist changes during a journey.

What is the change in velocity of the cyclist in the first 20 seconds of the journey? Tick (✓) one box.

Determine the acceleration of the cyclist during the first 20 seconds of the journey. Use your answer from Question 02.6 Use the equation:

Complete the sentence. Choose the answer from the box.

deceleration speed velocity

Between 30 and 40 seconds the cyclist moves with

The cyclist travels from home to school. Figure 7 shows the route the cyclist followed.

Draw an arrow on Figure 7 to show the displacement of the cyclist.

The thinking distance and braking distance for a car vary with the speed of the car.

Explain the effect of two other factors on the braking distance of a car. Do not refer to speed in your answer.

Which equation links acceleration (a), mass (m) and resultant force (F). Tick (✓) one box.

The mean braking force on a car is 7200 N. The car has a mass of 1600 kg. Calculate the deceleration of the car.

Figure 18 shows how the thinking distance and braking distance for a car vary with the speed of the car.

Determine the stopping distance when the car is travelling at 80 km/h.

Figure 19 shows part of the braking system for a car.

Which equation links area of a surface (A), the force normal to that surface (F) and pressure (p)? Tick (✓) one box.

When the brake pedal is pressed, a force of 60 N is applied to the piston. The pressure in the brake fluid is 120 000 Pa. Calculate the surface area of the piston. Give your answer in standard form. Give the unit.

The thinking distance and braking distance for a car vary with the speed of the car.

Explain the effect of two other factors on the braking distance of a car. Do not refer to speed in your answer.

Which equation links acceleration (a), mass (m) and resultant force (F). Tick (✓) one box.

The mean braking force on a car is 7200 N. The car has a mass of 1600 kg. Calculate the deceleration of the car.

Figure 1 shows how the thinking distance and braking distance for a car vary with the speed of the car.

Determine the stopping distance when the car is travelling at 80 km/h.

Figure 2 shows part of the braking system for a car.

Which equation links area of a surface (A), the force normal to that surface (F) and pressure (p). Tick (✓) one box.

When the brake pedal is pressed, a force of 60 N is applied to the piston. The pressure in the brake fluid is 120 000 Pa. Calculate the surface area of the piston. Give your answer in standard form. Give the unit.

An aircraft travels at a constant velocity. How is the velocity of the aircraft different to the speed of the aircraft?

Figure 11 shows one of the engines on the aircraft.

Air is taken into the front of the engine and pushed out of the back of the engine. Explain the effect this has on the engine.

Figure 12 shows a distance-time graph for the aircraft.

Determine the speed of the aircraft.

Write down the equation that links acceleration (a), change in velocity (Δ v) and time taken (t).

At a different stage of the flight, the aircraft was travelling at a velocity of 250 m/s. The aircraft then decelerated at 0.14 m/s². Calculate the time taken for the aircraft to decelerate from 250 m/s to 68 m/s.

Write down the equation that links distance (s), force (F) and work done (W).

When the aircraft landed, it travelled 2000 m before stopping. The work done to stop the aircraft was 140 000 000 J. Calculate the mean force used to stop the aircraft.

Mean force = N

A student investigated the acceleration of a trolley. Figure 13 shows how the student set up the apparatus.

Before attaching the mass holder the student placed the trolley at the top of the runway. The trolley rolled down the runway without being pushed. What change to the apparatus in Figure 13 could be made to prevent the trolley from starting to roll down the runway? Tick (✓) one box.

The student attached the mass holder to the string. The string rubbed along the edge of the bench as the mass holder fell to the floor. Suggest what the student could do to prevent the string from rubbing.

The light gate and data logger were used to determine the acceleration of the trolley. The student increased the resultant force on the trolley and recorded the acceleration of the trolley. Table 4 shows the results.

Figure 14 is an incomplete graph of the results.

Complete Figure 14.

• Choose a suitable scale for the x-axis.

• Plot the results.

• Draw a line of best fit.

Describe the relationship between the resultant force on the trolley and the acceleration of the trolley.

Describe how the investigation could be improved to reduce the effect of random errors.

Write down the equation that links acceleration (a), mass (m) and resultant force (F).

The resultant force on the trolley was 0.375 N. The mass of the trolley was 0.60 kg. Calculate the acceleration of the trolley. Give your answer to 2 significant figures.

A student investigated the acceleration of a trolley. Figure 1 shows how the student set up the apparatus.

Before attaching the mass holder the student placed the trolley at the top of the runway. The trolley rolled down the runway without being pushed. What change to the apparatus in Figure 1 could be made to prevent the trolley from starting to roll down the runway? Tick (✓) one box.

The student attached the mass holder to the string. The string rubbed along the edge of the bench as the mass holder fell to the floor. Suggest what the student could do to prevent the string from rubbing.

The light gate and data logger were used to determine the acceleration of the trolley. The student increased the resultant force on the trolley and recorded the acceleration of the trolley. Table 1 shows the results.

Figure 2 is an incomplete graph of the results.

Complete Figure 2.

• Choose a suitable scale for the x-axis.

• Plot the results.

• Draw a line of best fit.

Describe the relationship between the resultant force on the trolley and the acceleration of the trolley.

Describe how the investigation could be improved to reduce the effect of random errors.

Write down the equation that links acceleration (a), mass (m) and resultant force (F).

The resultant force on the trolley was 0.375 N. The mass of the trolley was 0.60 kg. Calculate the acceleration of the trolley. Give your answer to 2 significant figures.

Figure 8 shows a student playing with a remote-controlled car.

The remote control transmits radio waves to the car aerial. The transmitted radio waves have a frequency of 320 MHz. speed of radio waves = 3.0 10⁸ m/s Calculate the wavelength of the radio waves. Give the unit.

The car aerial is connected to an electrical circuit in the car. Describe what happens in the electrical circuit when the car aerial absorbs radio waves.

The car produces sound waves. Give two ways in which radio waves are different to sound waves.

Figure 9 shows the distance-time graph for the first 30 seconds of the car’s motion.

Describe the motion of the car during the first 30 seconds.

Determine the speed of the car 20 seconds after it started to move.

A different car accelerated from 0.12 m/s to 0.52 m/s. The acceleration of the car was 0.040 m/s². The work done to accelerate the car was 0.48 J. Calculate the resultant force needed to accelerate the car.

Explain why the car has a maximum speed.

Figure 1 shows an athlete on starting blocks waiting to start a 100 metre race.

Complete the sentence. Choose the answer from the box.

The force from the athlete pushing backwards on the starting blocks is the force from the starting blocks pushing forwards on the athlete.

Figure 2 shows a distance-time graph for the athlete from the moment the race starts.

Three parts of the distance-time graph are labelled J, K and L. Draw one line from each of the labels to the correct description of the athlete’s motion for that part of the graph.

What distance does the athlete travel after the end of the race before stopping?

Calculate the average speed of the athlete between the start and finish of the 100 metre race. Use the equation:

The athlete runs faster than a typical person. What is the average running speed of a typical person in metres per second?

Tick (✓) one box.

The following statements describe parts of a short train journey between two railway stations. Part A: The train accelerates at a constant rate from 0 m/s to 20 m/s in 40 s Part B: The train travels at a constant velocity for 260 s Part C: The train decelerates at a constant rate coming to a stop in 60 s

During which part of the journey is the resultant force on the train zero? Tick (✓) one box.

Figure 16 shows part of the velocity-time graph for the train journey. Complete Figure 16 showing part B and part C of the train journey.

Figure 16

Write down the equation which links acceleration, change in velocity and time taken.

Another train accelerated at 1.15 m/s² for 22.0 s Calculate the increase in velocity of the train.

An adult of mass 80 kg has more inertia than a child of mass 40 kg What is inertia?

A teacher demonstrated the idea of a safety surface. She dropped a raw egg into a box filled with pieces of soft foam. The egg did not break. Figure 10 shows the demonstration.

Explain why the egg is less likely to break when dropped onto soft foam rather than onto a concrete floor.

Figure 11 shows a child on a playground swing. The playground has a rubber safety surface.

A child of mass 32 kg jumped from the swing. When the child reached the ground she took 180 milliseconds to slow down and stop. During this time an average force of 800 N was exerted on her by the ground.

Calculate the velocity of the child when she first touched the ground. Use the Physics Equations Sheet.

Figure 7 shows four blocks of different materials floating on water. The four blocks are the same volume.

Which of the blocks has the smallest weight? Tick one box.

Figure 8 shows a lifebuoy next to a deep swimming pool.

The lifebuoy has a mass of 2.5 kg. gravitational field strength = 9.8 N/kg Calculate the weight of the lifebuoy. Use the equation: weight = mass × gravitational field strength

When thrown into the water the lifebuoy floats. The two forces acting on the lifebuoy are the weight of the lifebuoy downwards and upthrust upwards. How big is the upthrust on the lifebuoy compared to the weight of the lifebuoy? Tick one box.

Write down the equation which links acceleration, mass and resultant force.

A rope is used to pull the lifebuoy to the side of the swimming pool. A resultant force of 4.0 N acts on the lifebuoy. The mass of the lifebuoy is 2.5 kg. Calculate the acceleration of the lifebuoy.