A car in a repair shop is moved 2.45 m by a hydraulic lift. The work done on it by gravity is -43.9 kJ. What?

Question

A car in a repair shop is moved 2.45 m by a hydraulic lift. The work done on it by gravity is -43.9 kJ. What is the car's mass, and which way did it move?
1620 kg, down
1940 kg, up
1830 kg, up
2110 kg, down

Answer 1

Since gravity did negative work, there was an increase in the potential energy of the car, which means it was raised up.
PE=m*g*h
43,900=m*9.81*2.45

solve for m

j