Distance-time graphs

A person has been for a walk.

Figure 9 shows the distance–time graph for the walk.

Some quantities are scalar quantities and others are vector quantities.

Which of the following are scalar quantities?

Tick (✓) two boxes.

What was the total distance walked by the person in 2000 seconds?

Calculate the average speed of the person during the 2000 seconds.

Use your answer to Question 05.2

Use the equation:

Which section of Figure 9 shows the person walking the slowest?

Give a reason for your answer.

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The person walked slowest when going up some steps.

Complete the sentence.

Choose the answer from the box.

When walking up the steps, the person did more work against the

On another day, the person ran the same route.

What is a typical speed for a person running?

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Figure 17 shows the Hubble Space Telescope orbiting the Earth.

What name is given to an object that orbits a planet? Tick (✓) one box.

The Earth exerts a gravitational force on the Hubble Space Telescope. Draw an arrow on Figure 17 to show the gravitational force.

Figure 18 shows how the distance travelled by the Hubble Space Telescope during its orbit changes with time.

The gradient of the line in Figure 18 gives the speed of the Hubble Space Telescope. Determine the speed of the Hubble Space Telescope. Give your answer in km/s.

The Hubble Space Telescope can detect the visible light spectra from distant galaxies. The visible light spectra from stars and galaxies include dark lines at specific wavelengths. Figure 19 shows the visible light spectra from the Sun and three galaxies.

Which galaxy is moving away from the Earth the fastest? Tick (✓) one box.

Which galaxy is the furthest away from the Earth? Tick (✓) one box.

New scientific observations indicate that many galaxies rotate too quickly for the known mass of the stars they contain. Why is it important that new scientific observations are peer reviewed? 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.

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

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.

An aeroplane is 4000 m above the Earth’s surface. A skydiver jumps from the aeroplane and falls vertically. Figure 15 shows the distance the skydiver falls during the first 12 seconds after jumping.

Figure 16 shows part of the free body diagram for the skydiver three seconds after jumping. Complete the free body diagram for the skydiver.

Explain the changing motion of the skydiver in terms of the forces acting on the skydiver.

Use Figure 15 to determine the speed of the skydiver between 7 seconds and 12 seconds.

In 2012 a skydiver jumped from a helium balloon 39 000 metres above the Earth’s surface. The skydiver reached a maximum speed of 377 m/s Jumping from 39 000 metres allowed the skydiver to reach a much higher speed than a skydiver jumping from 4000 metres. Explain why.