Question

Spring Constant K question.
If it says that the spring force constant is 90 lb PER foot, then don't you need to multiply that value times the natural length of the spring?
e.g.
Natural length unstretched is 13 inches (13/12 ft), so isn't K 90*13/12?
the solution says its a straight 90, but that doesn't make sense.

Answer 1

Things you need to understand:

Spring force=-kx

Where k is spring constant, x is extension

k is always a fixed constant. You don't have to multiply it by natural length.

Answer 2

okay thank vm!

Answer 3

yw :)