AS Daily A Level Physics question
In a straight-track lab, a trolley starts from rest and moves with constant acceleration. If the time of travel is doubled (with the same motion continuing), what happens to the displacement from the start?
Answer
The correct answer is D.
Correct: D — It increases by a factor of four. A assumes distance is proportional to time as if speed were constant; with constant acceleration from rest, average speed is higher over the longer interval so distance grows faster than time. B still underestimates it; doubling the time from rest does not merely triple the displacement. C is impossible because with non-zero acceleration for longer, the trolley continues to cover additional distance. D is correct for uniform acceleration from rest: displacement scales with the square of time, so doubling time makes the displacement four times larger.