Question

A boy pulls a sled with a force of 10.0 lb for 100.0 ft. The rope attached to the sled is at an angle 30.0 ̊ above the horizontal. (a) How much work is done? (b) If the boy moves the sled 100.0 ft in 45 s, find his power output in horsepower.

Answer 1

work = force * displacement in direction of force

= 10.0 * 100 cos 30 = 866 ft lbs
power = 866/45 = 19.2ft lbs/s * ( 0.0018 hp / 1 ft lb/s) = 0.0346 hp