A helicopter is lifting an 800-pound unit at a rate of 200 feet per minute. How many horsepower of work energy is the helicopter using in the process?
A) 3.863 hp.
B) 4.517 hp.
C) 4.848 hp.
D) 5.209 hp.

Question

Quizplus · Accepted Answer

Power(W) = Work Energy / Time
Work Energy = Force * Distance
Force = Weight = 800 lb
Distance = Rate * Time = (200 ft/min) * (1 min) = 200 ft
Work Energy = (800 lb) * (200 ft) = 160000 ft-lb
Time = 1 min
Power = (160000 ft-lb / 1 min) / 745.7 W/hp = 214.58 W / 745.7 W/hp = 0.288 hp
Therefore, the helicopter is using 4.848 (approximately 4.9) horsepower of work energy in the process.

A Helicopter Is Lifting an 800-Pound Unit at a Rate