If you lift a 40 lb. rock 5 ft. from the ground, how much work have you done?
200 ft. lb.
Explanation
Work is force times distance. In this case, the force is the weight of the rock so: \(W=f \times d=40 \mathrm{lb.} \times 5 \mathrm{ft.}=200 \mathrm{ft.} \mathrm{lb.}\)