Answer:
The change in gravitational potential energy is -1.80x10⁵ J.
Explanation:
The change in gravitational potential energy is given by:
[tex] \Delta E_{p} = E_{p_{f}} - E_{p_{i}} [/tex]
[tex] \Delta E_{p} = mgh_{f} - mgh_{i} [/tex]
Where:
"i" is for final and "f" for final
m: is the mass
g: is the gravity = 9.81 m/s²
h: is the height
For the car and the passengers we have:
[tex] \Delta E_{p} = m_{T}g(h_{f} - h_{i}) = (750 kg + 135 kg)9.81 m/s^{2}(0 - 20.7 m) = -1.80 \cdot 10^{5} J [/tex]
The minus sign is because when the elevator car and the passengers are up they have a bigger gravitational potential energy than when they are in the ground.
Therefore, the change in gravitational potential energy is -1.80x10⁵ J.
I hope it helps you!