Question

A warehouse worker pushes a 19.1 kg box, increasing its speed from rest to 3.40 m/s. This acceleration occured over a period of 0.933 seconds. How much power did the worker produce?
Select one:
a.
118 W
b.
110 W
c.
126 W
d.
103 W

Answer 1

Answer:

a. 118 W

Explanation:

Power is rate of doing work.

We must ASSUME that friction is not relevant as we are given no clue as to its values. We must also ASSUME the surface is horizontal.

The work done changes the kinetic energy

W = ½m(v₁² - v₀²) = ½(19.1)(3.40² - 0²) = 110 J

as this occurs in 0.933 s, power is

P = 110 / 0.933 = 118 W(atts)