W = 1/2 kx^2
18 = 1/2 k * 16
k = 9/4
So, 1/2 * 9/4 * (4+2) = 6.75 ft-lb
Not sure whether you wanted the total work, or the additional work...
It takes 18 foot-pounds of work to stretch a spring 4 inches
from its natural length. Find the work you need to stretch
the spring an additional 2 inches.
1 answer
0 answers