Bodies P and Q move equal distances from rest. P has acceleration 2a for the first half distance and a for the second half; Q has acceleration a for the first half and 2a for the second half. For the whole journey:
Options

Question

Bodies P and Q move equal distances from rest. P has acceleration 2a for the first half distance and a for the second half; Q has acceleration a for the first half and 2a for the second half. For the whole journey:

Options

G1 Physics · Accepted Answer

For each body, final speed after the full distance follows v²=2∫a dx. Since both experience the same total ∫a dx, their maximum/final speeds are equal. But P gets the larger acceleration first, so it gains speed earlier and completes the journey in less time; therefore its average speed is larger. Hence option A.