Speed and motion graphs — return questions

1. state / calculate

Keep the lesson closed. (a) State what is meant by speed and by velocity. (b) A runner covers 400 m in 80 s. Calculate her speed. (c) On a distance–time graph, a straight line rises from 100 m at 10 s to 250 m at 40 s. Calculate the speed. (d) A car travels 3.0 km in 4.0 minutes, then waits 1.0 minute. Calculate its average speed in m/s. (e) On a distance–time graph, what does each of these show: a flat line; a straight falling line; a curve that gets steeper? (f) On paper, sketch the distance–time graph of a girl who stands 5 m from a wall for 10 s, then walks away from it at a steady 1.5 m/s for 20 s, then stands still for 10 s.

(a) Speed and velocity

(b) The runner's speed

(c) Speed from the graph

(d) Average speed of the car

(e) What the three shapes show

(f) Your sketch: axes, the three parts, times and distances

2. state / calculate

Keep the lesson closed. (a) On a speed–time graph, what do these mean: a line along the time axis; a flat line above it; a rising line; a falling line? (b) What does the area under a speed–time graph give? (c) A car speeds up evenly from rest to 15 m/s in 6.0 s. Calculate the distance it travels in that time. (d) A runner's speed, worked out from a motion sensor's distance readings, is given every 2 s (table). Plot the speed–time graph on paper, then use it to find how far she runs in the 8 s.

(a) What each shape means

(b) What the area gives

(c) Distance travelled by the car

(d) Your plot and the distance, with working