AS Daily A Level Physics question
A trolley on a smooth track is pulled by the same steady horizontal force in two runs. In the second run, the trolley’s mass is doubled by adding weights. Ignore friction. What happens to its acceleration?
Answer
The correct answer is C.
Correct: C — Halves because the same force acts on twice the mass. A is wrong because acceleration depends on both force and mass; increasing mass reduces acceleration even if the force is unchanged. B is wrong because increasing mass does not increase acceleration when the force is fixed; it reduces it. C is correct because for a fixed force, acceleration is inversely related to mass, so doubling mass halves the acceleration. D is wrong because any non-zero net force produces a non-zero acceleration; it does not drop to zero just because the object is heavier.