A force of 40N stretches as wire through 3.0cm what will stretch it through 5.0cm? an through what length will the force of 100N stretch it?
(A) 5/3 the stretch, so 5/3 the force
(B) 5/2 the force, so 5/2 the stretch
F=ke, where; F is force, k is spring constant and e is extension
k=F/e
k=40/0.03
k=4000/3 N/m
when e=5cm=0.05m
then, F=ke
=4000/3×0.05
=66.667N
when F=100N then, e=F/k
=100/(4000/3)
=0.075m=7.5cm