P1 quiz: motion
Ten think-time questions on speed, average speed, scalars and vectors, distance-time graphs and speed-time graphs.
Transcript
Ten quick questions on speed, velocity and motion graphs. Listen, think, then check your answer.
Question one. What is the unit of speed? A, metres per second. B, metres per second squared. Or C, kg.
The answer is A, metres per second. Speed is measured in metres per second. Acceleration is in metres per second squared.
Question two. A runner covers 90 metres in 18 seconds. What is the speed? A, 5 metres per second. B, 72 metres per second. Or C, 0.2 metres per second.
The answer is A, 5 metres per second. Speed equals distance divided by time. 90 divided by 18 equals 5 metres per second.
Question three. A car travels at 20 metres per second for 30 seconds. What distance does it travel? A, 600 metres. B, 50 metres. Or C, 0.67 metres.
The answer is A, 600 metres. Distance equals speed times time. 20 times 30 equals 600 metres.
Question four. Average speed is: A, total distance divided by total time. B, total time divided by total distance. Or C, the biggest speed in the journey.
The answer is A, total distance divided by total time. Average speed is total distance divided by total time. Stops count as time.
Question five. A bus travels 800 metres in 200 seconds. What is its average speed? A, 2 metres per second. B, 4 metres per second. Or C, 16 metres per second.
The answer is B, 4 metres per second. 800 divided by 200 equals 4 metres per second.
Question six. Which of these is a vector? A, speed. B, distance. Or C, velocity.
The answer is C, velocity. Velocity has size and direction. Speed and distance have size only.
Question seven. On a distance-time graph, a horizontal line means the object is: A, moving at constant speed. B, stationary. Or C, accelerating.
The answer is B, stationary. The distance is not changing. So the object is stationary.
Question eight. The gradient of a distance-time graph gives the: A, speed. B, acceleration. Or C, distance.
The answer is A, speed. Gradient is change in distance divided by change in time. That is the speed.
Question nine. A speed-time graph slopes downwards. The object is: A, accelerating. B, decelerating. Or C, stationary.
The answer is B, decelerating. The speed is getting smaller. So the object is decelerating.
Question ten. The area under a speed-time graph is the: A, acceleration. B, distance travelled. Or C, time taken.
The answer is B, distance travelled. The area under a speed-time graph is the distance. The gradient is the acceleration.
Quiz complete. Review any topic you missed, and watch the video again.
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