Question

The spring in a toy rocket launcher has a spring constant of 13 N/m. How far must you compress the spring to cause it to exert a force of 2.5 N?
A. 5.2 m
B. 0.42 m
C. 0.19 m
D. 0.28 m

Answer 1

Hooke's law states that the restoring force in a spring is given by
\[F=-kx\]where F is the restoring force in the spring, k is the spring constant, and x is the elongation or compression of the spring. The negative sign here is to indicate that the restoring force is in the opposite direction to the extension or compression of the spring. In your problem you are given k and F and must solve for x. A simple rearrangement of the equation is all that's required.