C) 500,000 J
The change in potential energy is ...
Mgh = (1000 kg)(9.8 m/s^2)(50 m) = 490,000 J . . . . roughly matches C
_____
Comments on the problem
The efficiency of the motor is unknown, so the amount of energy spent as heat is unknown.
In the equation above, we have used M for mass, and m for meters. The acceleration due to gravity is approximately 9.8 m/s^2, varying depending on location and height above the Earth. The "standard" value for g will add a few more joules to this value, but will not make it 500,000.
The answer would be 500,000 J
Since the change in the potential energy is:
Mgh = (1000 kg)(9.8 m/s^2)(50 m) = 490,000 J
This answer is close enough for 500,000 J to be the correct answer
Hope i helped!
