Question

Figure 9 (below) is a graph of the force as a function of stretch for a ceratin spring. Is the force applied "to" or "by" the spring? please explain why.

Answer 1

I ll give you a clue
when you apply a force TO the spring (meaning an external force), the displacement is in the same direction.. make sense? u pull the spring , the spring comes towards u, u push the spring, the spring goes away from you..

but when the force is applied BY the spring (its internal spring force), then the force and displacement are in opposite directions

so ... now can u figure out?

Answer 2

oh thanks buddy! ;p

Answer 3

Your welcme :)