Question 5
The displacement–time graph below shows how an object moved along a straight path.
| t (s) | 0 | 4 | 6 | 8 |
|---|---|---|---|---|
| s (m) | 0 | 10 | 10 | 0 |
How far did the object travel, and in what time, before it came to a stop?
The right answer is the one marked above.
10 m in 4 s. The line on the graph rises from 0 until t = 4 s, and from there it runs flat.
The point where the line goes flat — (4, 10) — is the moment the object stopped. Up to there the displacement grew from 0 to 10 m, over 4 s.
8 s is the time the whole graph covers — but from t = 6 s to t = 8 s the line slopes downwards, so the object is travelling back during that stretch.