Respuesta :

Answer:

ΔU = -17640 J

Explanation:

use the formula ΔU = mgΔh for the change in potential energy

m = 60 kg

g = 9.8 m/s^2

Δh = 60 - 90 = -30 m

ΔU = mgΔh

ΔU = 60 * 9.8 * -30

ΔU = -17640 J

there was a decrease of 17640 joules in potential energy

Decrease of joules in it