Question 1
The velocity–time graph of an object is shown below.
| t (s) | 0 | 5 |
|---|---|---|
| v (m s⁻¹) | 0 | 20 |
What is the object's acceleration?
The right answer is the one marked above.
4 m s-2. The gradient of a velocity–time graph is the acceleration:
acceleration = (20 − 0) m s-1 ÷ (5 − 0) s = 4 m s-2
The graph is a straight line because the velocity changes by the same amount in every second — this is motion with a uniform acceleration.
20 m s-2 is the change in velocity, not the acceleration; it still has to be divided by the time.