Number 5
3 marks · NormalA car travels 153 kilometres in 2 hours 35 minutes. Give the average speed in metres per second. Give your answer to 2 decimal places.
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16.46 m/s (±0.01)
Common mistakes: Incorrect conversion of time to seconds
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Marking points
M1 · 1 mark · Converts 153 km to metres (153,000 m) and time to seconds (2 × 3600 + 35 × 60 = 9300 s).
M2 · 1 mark · Uses speed = distance / time.
A1 · 1 mark · Final answer correct to 2 decimal places: 16.45–16.47 m/s accepted.
Worked solution
Distance = 153 km = 153,000 m. Time = 2 hr 35 min = (2 × 3600) + (35 × 60) = 9300 s. Speed = distance / time = 153,000 / 9300 = 16.4516... ≈ 16.46 m/s (2 d.p.).