Question

The distance between the sixth and the eleventh floors of a building is 30.0m. The combined mass of the elevator and its contents is 1350 kg. a) find the gravitational potential energy of the elevator when it stops at the eighth floor, relative to the sixth floor.

Source https://www.physicsforums.com/threads/finding-gravitational-potential-energy.310390/

Answer 1

$11-6=5$

$30/5=6(m)$

$\Delta h=6\cdot(8-6)=12(m)$

$\Delta E=mg\Delta h=1350\cdot9.81\cdot12=1.59\cdot10^5(J)$