Question

Hiro walks up a flight of stairs in his apartment building. Later in the day, he runs up the same flight of stairs.

Which statement about work and power describes Hiro’s actions?

He did more work running than walking.
He did more work walking than running.
He had more power running than walking.
He had more power walking than running.

Answer 1

He had more power running than walking.

Explanation: The work against gravity (gain in gravitational potential energy) is the same for the same flight of stairs. Power = work / time, and running takes less time, so the average power is larger when he runs.