1. 1
   A train travels along a straight, level track between two stations. A distance–time graph is plotted for the whole 20-minute journey, showing the train's distance from the first station at each point in time.

   (a)

   Which feature of the graph shows that the train is stationary?

   [1 mark]

   • AA straight line sloping upwards
   • BA straight line sloping downwards
   • CA curve that gets steeper
   • DA horizontal (flat) line

   (b)

   Between the 5th and 10th minute of the journey, the distance–time graph is a straight line rising steadily from 4 km to 9 km. What is the train's speed during this section?

   [1 mark]

   • A0.5 km/min
   • B1 km/min
   • C5 km/min
   • D9 km/min

   (c)

   Explain what feature of a distance–time graph would show that the train is speeding up, and describe how this differs from the graph of an object moving at constant speed.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   In 1997, a jet-powered car attempted a land speed record by driving in a straight line across a 12 km desert flat, then returning along the same course in the opposite direction.

   (a)

   In 1997, a jet-powered car set a land speed record by driving in a straight line across a desert flat and back along the same course. Which quantity below is the same for both the outward and return runs, but whose direction differs between them?

   [1 mark]

   • ASpeed
   • BDistance
   • CVelocity
   • DTime

   (b)

   The car covered the 12 km outward run in 40 seconds. What was its average velocity during this run, taking the outward direction as positive?

   [1 mark]

   • A300 m/s
   • B0.3 m/s
   • C3.3 m/s
   • D−300 m/s

   (c)

   On the return run, the car covered the same 12 km course but took 42 seconds because strong crosswinds slowed it down. Calculate the car's average velocity for the return run, taking the outward direction as positive, and explain why the record-setting speed is usually calculated from the average of both runs rather than from a single run.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   An ambulance is called to an emergency 8 km from the hospital along a route with several sets of traffic lights. The journey there takes 9 minutes in total, and the ambulance travels at a range of different speeds throughout, slowing at junctions and speeding up on clear stretches of road.

   (a)

   Explain what is meant by 'average speed' in this context, and calculate the ambulance's average speed for the journey in km/h.

   [3 marks]

   (b)

   On the return journey to the hospital with the patient on board, the ambulance driver takes a different, longer route of 11 km to avoid roadworks, completing it in 10 minutes. Calculate the average speed for the return journey in km/h, and explain whether this journey had a greater or smaller average speed than the outward journey.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   Conservationists track a migrating bird using a small GPS tag that records its position at regular intervals during a long-distance flight over open ocean. The bird sometimes flies directly into a headwind and at other times has a tailwind pushing it along, and its flight path curves around a large storm system partway through the journey.

   (a)

   Explain, using the concepts of distance, displacement, speed and velocity, how the conservationists could use the GPS data to work out the bird's average speed and average velocity for the whole flight, and explain why these two values might be very different if the bird did not fly in a straight line.

   [6 marks]

   (b)

   The GPS data shows the bird covered 2400 km of actual flight path in 30 hours, but its straight-line displacement from start to finish was only 2000 km due to the detour around the storm. Calculate the bird's average speed and the magnitude of its average velocity for the flight, and explain what this comparison reveals about the extra energy the bird likely used because of the detour.

   [6 marks]

   Total for question 4: 12 marks

End of questions