Question 7
A child climbs a staircase, walking 8 m along the steps and rising 4 m vertically. Which distance goes into h in Ep = m g h?
The right answer is the one marked above.
4 m, the vertical height gained. Gravity acts vertically, and only displacement along a force counts as work done against it.
This is the same rule as the work formula, which takes the displacement in the direction of the force rather than the total distance travelled.