AS Daily A Level Physics question
In a lab, a trolley starts from rest on a smooth, level track and is pulled by a constant force so it accelerates uniformly. If the pulling time is doubled, what happens to the distance travelled during the pull?
Answer
The correct answer is A.
Correct: A — It becomes four times larger. A is correct because from rest under constant acceleration, displacement in time t increases with t^2, so doubling t makes the distance four times bigger. B is wrong because while final speed doubles, the average speed over the interval also doubles, so distance grows faster than linearly (it quadruples, not doubles). C is wrong because a longer time accelerating must give a greater distance. D is wrong because it mixes up relationships; distance from rest does not scale with √t but with t^2.