AS Daily A Level Physics question
A smooth lab trolley is pulled with a constant horizontal force using a spring balance. Friction is negligible. You then load the trolley so its mass is doubled, but you pull with the same force as before. What happens to the trolley’s acceleration?
Answer
The correct answer is B.
Correct: B — It halves. A — Assumes a heavier object accelerates more for the same pull, but increasing mass reduces acceleration for a given force. B — For a fixed pull, doubling the mass makes acceleration inversely proportional to mass, so it becomes half. C — Ignores that acceleration depends on both the applied force and the mass; with the same force, more mass means less acceleration. D — Suggests a smaller reduction than half, but with the same force and double the mass the acceleration must be exactly half, not just slightly reduced.