A force of 20 pounds stretches a spring 11 inches in an exercise machine. Find the work done in stretching the spring 2 feet from its natural position.
A) ft-lb
B) ft-lb
C) ft-lb
D) ft-lb
E) ft-lb

Question

A force of 20 pounds stretches a spring 11 inches in an exercise machine. Find the work done in stretching the spring 2 feet from its natural position.
A) ft-lb 
B) ft-lb 
C) ft-lb 
D) ft-lb 
E) ft-lb

Quizplus · Accepted Answer

First, we need to find the spring constant, k, using Hooke's law:

F = kx
20 = k(11)
k = 20/11

Now, we can use the work formula:

W = (1/2) kx^2

W = (1/2) * (20/11) * (24^2)

W ≈ 164.94 ft-lb

Rounding to the nearest hundredth gives us choice D: 11eaa595_64f9_bda8_a696_5589772e8455_TB4584_11_TB4584_11 ft-lb.

A Force of 20 Pounds Stretches a Spring 11 Inches