Question

A man is carrying a box of 2 kg in his hands while moving on a plane. If he moves 40 m with an acceleration of 0.5 ms^-2, then calculate the work done on the box by the man during the motion.

Answer 1

Given; m = 2kg; a = 0.5 ms^-2, d = 40m; W = ?
Force applied by the man on the box during accelerated motion,
F= ma = 2 × 0.5 = 1.0 N v
∵ The directions of force and displacement are the same.
∴ θ = 0
∴ cos0 1
Hence W = Fdcosθ = 1 × 40 × 1
or W = 40 J