Gravitational potential energy change uses ΔPE = mgh

Steps:

• Convert mass to kg: 3000 g = 3 kg.
• Estimate height drop from hand to foot: ≈1 m.
• Use g ≈ 10 m/s².
• Calculate ΔPE = 3 kg × 10 m/s² × 1 m = 30 J.

Why A is correct:

• ΔPE = mgh formula with m=3 kg, g=10 m/s², reasonable h=1 m yields exactly 30 J.

Why the others are wrong:

• B: Requires h=10 m, unrealistically high for hand-to-foot drop.
• C: Requires h=100 m, impossible for human height.
• D: Requires h=1000 m, absurdly large.

Final answer: A