Describing motion along a line

A student went on a cycling journey that lasted for three days.

The student recorded information about the journey using a cycling app on a mobile phone.

At the start of the journey, the student travelled along a straight road to a road junction.

A map on the cycling app showed the road.

Figure 5 shows the map.

The scale of the map is 1 cm: 20 m

Calculate the distance travelled by the student between the start and the

road junction.

Use Figure 5.

The bicycle had a mass of 15 kg.

gravitational field strength = 9.8 N/kg

Calculate the weight of the bicycle.

Use the equation:

weight = mass × gravitational field strength

Figure 6 shows a velocity–time graph for a downhill part of the journey.

The gradient of the graph represents acceleration.

How does Figure 6 show that the acceleration was constant?

As the student accelerated downhill, the forward force on the student was 250 N.

The work done by the forward force was 4500 J.

Calculate the distance travelled as the student accelerated downhill.

Use the equation:

Most of the roads on the journey were not straight.

Figure 7 shows a map of the route taken for the whole journey.

The line in Figure 7 represents the total distance travelled when the student reached the end of the journey.

How does the total distance travelled compare with the magnitude of the displacement of the student from the start?

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Why is distance a scalar quantity?

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Figure 8 shows the distance travelled by the student each day.

Calculate the total distance travelled by the student.

Use Figure 8.

In a dog-sled race, a team of dogs pull on a rope attached to a sled.

Figure 12 shows a dog-sled team.

Use the Physics Equations Sheet to answer questions 06.1 and 06.2.

What equation links distance travelled, speed and time?

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The longest dog-sled race in the world covers a distance of 1 500 000 m.

One team finished the race in a time of 670 000 s.

Calculate the average speed of this team during the race.

At the start of the race, 6 dogs pulled on the rope.

The average forward force on the sled from each dog was 370 N.

The backwards force on the sled from friction was 520 N.

Calculate the resultant force on the sled.

Figure 13 shows a distance–time graph for the sled at the start of the race.

What does the gradient of the graph in Figure 13 represent?

Later in the race, the sled moved at a constant speed along a flat, horizontal path.

What was the relationship between the size of the horizontal forces acting when the sled moved at a constant speed?

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The rope exerted a force on the sled when the sled was moving.

What is the Newton’s Third Law pair to the force of the rope on the sled?

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In a dog-sled race, a team of dogs pull on a rope attached to a sled.

Figure 1 shows a dog-sled team.

Use the Physics Equations Sheet to answer questions 01.1 and 01.2.

What equation links distance travelled, speed and time?

Tick () one box.

The longest dog-sled race in the world covers a distance of 1 500 000 m.

One team finished the race in a time of 670 000 s.

Calculate the average speed of this team during the race.

At the start of the race, 6 dogs pulled on the rope.

The average forward force on the sled from each dog was 370 N.

The backwards force on the sled from friction was 520 N.

Calculate the resultant force on the sled.

Figure 2 shows a distance–time graph for the sled at the start of the race.

What does the gradient of the graph in Figure 2 represent?

Later in the race, the sled moved at a constant speed along a flat, horizontal path.

What was the relationship between the size of the horizontal forces acting when the sled moved at a constant speed?

Tick () one box.

The rope exerted a force on the sled when the sled was moving.

What is the Newton’s Third Law pair to the force of the rope on the sled?

Tick () one box.

A triathlon race consists of swimming, cycling and running.

One athlete in a triathlon swims at a speed of 1.5 m/s.

How does the athlete’s swimming speed compare with the typical speed of a person walking?

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Figure 8 shows a speed–time graph for the athlete for the whole triathlon.

The cycling part of the race was on a straight road.

The work done by the forward force on the bicycle was 110 000 J.

Determine the mean forward force on the bicycle.

Use the Physics Equations Sheet.

Figure 8 is repeated below.

The first part of the run was on a circular track.

The time taken for the athlete to run round the track was 100 s.

Describe the velocity of the athlete during the first 100 s of the run.

Use Figure 8.

After running round the track once, the rest of the run was on a straight, horizontal road.

Explain how Figure 8 shows that the magnitude of the deceleration of the athlete increased.

Figure 1 shows a skydiver jumping from an aeroplane.

The skydiver is accelerating downwards.

Which force causes the skydiver to accelerate?

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Which force increases as the skydiver accelerates?

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Figure 2 shows the two forces acting on the skydiver a few seconds after jumping from the aeroplane.

Calculate the resultant force acting on the skydiver in Figure 2.

Eventually the skydiver stops accelerating and falls at a constant velocity.

What is the resultant force acting on the skydiver when falling at a constant velocity?

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What name is given to the constant velocity of the skydiver?

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Figure 3 shows a velocity–time graph for the skydiver.

How many seconds did the skydiver accelerate for?

Use Figure 3.

What was the constant velocity of the skydiver?

Use Figure 3.

After opening a parachute, the skydiver fell at a constant speed of 3.6 m/s for 25 seconds.

Calculate the distance travelled by the skydiver during this time.

Use the equation:

distance travelled = speed × time

Figure 6 shows an electronic whistle used by a referee in a football match.

When the button is pressed the whistle emits sound waves that travel through the air.

What is transferred by the sound waves as they travel through the air?

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What is a typical value for the speed of sound in air?

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The whistle can emit two different sound waves, A and B.

Figure 7 shows the two different sound waves as displayed on a screen.

The sound waves are drawn to the same scale.

Complete the sentences to describe a difference and a similarity between the two waves.

Choose answers from the box.

Difference

Similarity

Wave A has a frequency of 4.0 kHz.

Which of the following is the same as 4.0 kHz?

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Calculate the period of wave A.

Use your answer from Question 03.4 and the equation:

Sound waves in air are longitudinal waves.

Complete the sentence to describe a sound wave.

Choose answers from the box.

When sound waves travel through air they create areas

A safety test was carried out to determine how the speed of a car affects the stopping distance of the car.

At the start of the test the car was moving slowly.

Then the car accelerated at 5.8 m/s² for 2.5 s.

The final velocity of the car was 20 m/s.

Calculate the initial velocity of the car.

Use the Physics Equations Sheet.

The reaction time of the driver was measured.

How can the reaction time of the driver be used to calculate the thinking distance?

The car was driven at a constant speed. The driver applied the maximum braking force, and the braking distance was measured.

The test was repeated at different speeds.

Figure 8 shows the results.

Which of the following gives the relationship between the speed and the braking distance?

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During one test the brakes were applied with a force of 6250 N.

The deceleration of the car was 5.0 m/s².

The braking distance of the car was 14.4 m.

Determine the momentum of the car before the brakes were applied.

Use the Physics Equations Sheet.

Use Figure 8.

Momentum = kg m/s

Sound waves are longitudinal waves.

Figure 9 shows a sound wave.

Complete the labels on Figure 9. Choose answers from the box.

Which of the following is true for longitudinal waves? Tick (✓) one box.

Figure 10 shows a device a farmer uses to scare away birds.

The device emits a very loud sound. The farmer measures the sound emitted by the device at different distances from the device.

Figure 11 shows a visual display of the sound waves at different distances from the device. Both waves are drawn to the same scale.

Which property of the wave changes between 80 m and 200 m? Tick (✓) one box.

Figure 12 shows how the speed of the sound emitted by the device is affected by the

temperature of the air.

The farmer tests the device on a day when the temperature of the air is 15 °C. What is the speed of the sound emitted by the device when the temperature of the air is 15 °C?

The farmer stands a safe distance from the device. It takes a time of 0.20 s for the sound to travel from the device to the farmer. Calculate the distance between the device and the farmer. Use your answer to Question 04.4 and the equation: distance = speed × time

Explain how the time taken for the sound to reach the farmer is affected by the temperature of the air. Use Figure 12.

Figure 9 shows a child dropping a stone into water.

When the child drops the stone it passes the child’s feet with a velocity of 3.1 m/s. The child’s feet are 6.3 m above the water. acceleration due to gravity = 9.8 m/s² Calculate the velocity of the stone as it hits the water. Use the Physics Equations Sheet. Give your answer to 2 significant figures.

Velocity is a vector. Describe the velocity of the stone as it falls through the air. Assume there is no air resistance.

Figure 10 shows the stone just after it has entered the water.

As the stone moves through the water, the stone slows to a constant velocity. Explain why.

Figure 10 shows competitors in the wheelchair race at the London Marathon. The distance of the London Marathon is 42 000 m

Use the Physics Equations Sheet to answer questions 07.1 and 07.2.

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

During the race competitors work against air resistance. The work done against air resistance by the winner of the race was 3 360 000 J Calculate the average air resistance acting on the winner of the race.

Use the Physics Equations Sheet to answer questions 07.3 and 07.4.

Which equation links distance travelled, speed and time? Tick (✓) one box.

The distance of the London Marathon is 42 000 m The winning time for the race was 5600 seconds. Calculate the average speed of the winner of the race.

Explain why the speed of a competitor changes during the race.

Figure 3 shows competitors in the wheelchair race at the London Marathon. The distance of the London Marathon is 42 000 m

Use the Physics Equations Sheet to answer questions 02.1 and 02.2.

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

During the race competitors work against air resistance. The work done against air resistance by the winner of the race was 3 360 000 J Calculate the average air resistance acting on the winner of the race.

Use the Physics Equations Sheet to answer questions 02.3 and 02.4.

Which equation links distance travelled, speed and time? Tick (✓) one box.

The distance of the London Marathon is 42 000 m The winning time for the race was 5600 seconds. Calculate the average speed of the winner of the race.

Explain why the speed of a competitor changes during the race.

The distance a car travels during the driver’s reaction time is called the thinking distance.

Figure 9 shows how thinking distance depends on speed for a car.

Determine the driver’s reaction time. Use the Physics Equations Sheet.

Figure 10 shows how the velocity of a car changes during braking.

Determine the braking distance of the car.

Explain how the gradient of the line on Figure 10 shows that the resultant force on the car was not constant.

Scientists are developing a rocket aeroplane designed to travel much faster than jet aeroplanes.

The rocket aeroplane must accelerate along a runway to take off.

What would happen to the air resistance acting on the rocket aeroplane as it accelerates?

During the first 14 seconds the average speed of the rocket aeroplane on the runway will be 35 m/s.

Calculate the distance that the rocket aeroplane will travel during the first 14 seconds.

Use the equation:

distance travelled = average speed × time

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

When the rocket aeroplane travels a distance of 270 m on the runway the engines will do 54 000 000 J of work.

Calculate the average force exerted by the engines.

The rocket aeroplane will fly at a greater height than a jet aeroplane.

The height that an aeroplane flies at affects the radiation dose a passenger will receive each hour.

Table 2 shows the speed of each aeroplane and the radiation dose a passenger will receive each hour.

Exposure to ionising radiation has risks and possible consequences.

Evaluate the risks and possible consequences of flying in a rocket aeroplane and in a jet aeroplane.

Assume the same journey is made in each aeroplane.

Use values from Table 2.

Professional rugby players wear a tracking device that measures their velocity and acceleration.

Figure 9 shows a player wearing a tracking device.

The player is tackling another player who is running with the ball.

Velocity and acceleration are both vector quantities.

What is a vector quantity?

Tick (✓) one box.

Which of the following is a vector quantity?

Tick (✓) one box.

Figure 10 shows a velocity–time graph for the player running with the ball.

Determine the acceleration of the player between 0 and 1.6 s.

Describe the motion of the player between 3.4 s and 3.6 s.

The force exerted on the player when she is tackled causes her to accelerate.

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

The player accelerates at 25 m/s² when a resultant force of 1800 N acts on her.

Calculate the mass of the player.

The tracking device sends data to a computer during the game.

Suggest one advantage of the data being sent during the game.

Figure 1 shows a girl bowling a ball along a ten-pin bowling lane.

The girl is trying to knock down the ten pins at the end of the bowling lane. As the ball travels along the lane the velocity of the ball decreases.

Velocity is a vector. Which statement describes a vector? Tick (✓) one box.

Why does the velocity of the ball decrease as the ball travels along the lane? Tick (✓) one box.

The ball travels along the lane at an average speed of 4.5 m/s It takes the ball 4.0 seconds to travel the length of the lane. Calculate the length of the lane. Use the equation: distance travelled = speed × time

Figure 2 shows the ball hitting one of the pins.

Draw an arrow on Figure 2 to show the force of the pin on the ball.

The velocity of the pin changes from 0 to 12 m/s It takes 0.15 seconds for the velocity to change. Calculate the acceleration of the pin. Use the equation:

When the pin is struck it accelerates. Complete the sentences. Choose answers from the box. Each answer can be used once, more than once, or not at all.

The displacement of the pin from the girl. The mass of the pin. The kinetic energy of the pin.

Figure 4 shows two children playing table tennis.

The boy hits the ball from one end of the table.

Why does the velocity of the ball change when the boy hits it?

Tick (✓) one box.

The ball has an average speed of 11 m/s

The ball takes 0.25 s to travel the same distance as the length of the table.

Calculate the length of the table.

Use the equation:

distance travelled = speed × time

A table tennis ball should only be used if it bounces to at least 75% of the height it was dropped from.

A manufacturer tested a table tennis ball.

Table 1 shows the results.

Determine whether the ball can be used.

Use the data from Table 1.

Figure 5 shows two table tennis balls.

The balls are different sizes but have the same mass.

Both balls were dropped onto the table from the same height.

After they were dropped, the resultant force on the smaller ball was greater than the resultant force on the larger ball.

Explain why.

Some quantities are scalars and some are vectors.

Which of the following quantities are scalars?

Tick (✓) two boxes.

Give the difference between a vector quantity and a scalar quantity.

Bumper cars are a fairground ride and are designed to bump into each other.

Figure 5 shows two bumper cars moving towards each other.

The momentum of each bumper car is shown by an arrow.

Give two factors that affect the momentum of each bumper car.

The bumper cars crash into each other and stop.

Explain why both bumper cars stop after the crash.

Which of these is a scalar quantity?

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A woman cycled along a straight flat road.

Figure 1 shows how the woman’s velocity changed with time.

Which part of the graph shows the woman moving at constant velocity?

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Which part of the graph shows the woman stationary?

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Between points A and B the woman was accelerating.

Use Figure 1 to determine the total time for which she was accelerating.

Use Figure 1 to determine her increase in velocity between points A and B.

Calculate her acceleration between points A and B.

Use the equation:

Estimate how a typical cycling speed of 6 m/s compares with a typical walking speed.

Tick one box.