What is the gravitational work done when a 2 kg block falls 3 meters?

• A. 0 J
• B. 58.8 J
• C. -58.8 J
• D. 29.4 J

Answer: (B)

Gravity does work when the object moves in the direction of the force, and that work equals m g h, the mass times gravitational acceleration times the vertical displacement along gravity.

Here, m = 2 kg, g ≈ 9.8 m/s^2, and the block falls a vertical distance h = 3 m. So the work done by gravity is W = m g h = 2 × 9.8 × 3 = 58.8 J.

Because the motion is downward and gravity acts downward, the work is positive. The block’s gravitational potential energy decreases by 58.8 J, and that decrease equals the positive work performed by gravity. If you use a slightly different g (like 9.81), you’d get about 58.9 J, but the answer remains about 58.8 J.