Question

A 2.50 × 105 W motor is used for 26.4 s to pull a boat straight toward shore. How far does the boat move toward shore if a force of 4.20 × 104 N is applied by the motor?

157 m
1,590 m
1.11 × 106 m
6.60 × 106 m

Answer 1

Use P = W/t and W = Fd, so d = Pt/F.

d = (2.50×10^5 W)(26.4 s) / (4.20×10^4 N)
= 6.60×10^6 J / 4.20×10^4 N
= 1.57×10^2 m ≈ 157 m.

Answer: 157 m.