A warehouse worker uses a forklift to raise a crate of pickles on a platform to a height 2.75 m above the floor. The combined mass of the platform and the crate is 207 kg. If the power expended by the forklift is 1440 W, how long does it take to lift the crate?
A)37.2 s
B)5.81 s
C)3.87 s
D)18.6 s
E)1.86 s

Question

Quizplus · Accepted Answer

The potential energy gained by the crate and platform system is:

PE = mgh

Where m is the mass of the system, g is the acceleration due to gravity, and h is the height raised.

PE = (207 kg)(9.8 m/s^2)(2.75 m)
PE = 5568.825 J

The work done by the forklift is equal to the potential energy gained by the system:

W = PE
W = 5568.825 J

The time it takes to lift the crate can be found using the power equation:

P = W/t

Where P is the power expended by the forklift and t is the time it takes to lift the crate.

t = W/P
t = 5568.825 J / 1440 W
t ≈ 3.87 s

Therefore, the best choice is C) 3.87 s.

A Warehouse Worker Uses a Forklift to Raise a Crate