Work done by pulling force partitions into potential energy gain and friction work

Steps:

• Constant speed implies net force along ramp is zero: 400 N = 500 sinθ + f.
• Diagram gives height h = 1 m, distance d = 5 m, so sinθ = h/d = 0.2.
• Weight component down ramp = 500 × 0.2 = 100 N; friction f = 400 - 100 = 300 N.
• Gravitational potential energy E = 500 × 1 = 500 J; work against friction W = 300 × 5 = 1500 J.

Why A is correct:

• Values match force balance and work-energy principle: total work = Fd = 400 × 5 = 2000 J = E + W.

Why the others are wrong:

• B: Swaps W and E values, ignoring friction magnitude.
• C: Overestimates both by assuming larger d or h.
• D: Inflates W while understating E relative to calculations.

Final answer: A