Question: If the work required to stretch a spring 1 ft beyond
its natural length is 9 ft-lb, how much work W is needed to
stretch it 10 in. beyond its natural length? So my teacher today
gave us some physics equations and said to do this homework. Im
a little stuck on this, usually they give us the force required
to stretch a spring, not the work. Here is what i tried: Then I
did F=KX (hooke's law) to solve for the k constant of the spring
9 = K * 1 ft K = 9 So I now know that F = 9X (equation for force
of a spring when you know the k constant of that spring) And
then i said the: INTEGRAL of: 9x from 0-10/12 = Total work
needed to stretch the spring 10inches. I get 7.25, but this
answer is wrong.