# Jumping toy problem

## Homework Statement

A spring is compressed 1.5 cm and propels a 49g toy to a height of 45 cm.
a. Find the spring constant
b. The average power of the spring during propulsion.
c. The instantaneous power exerted when the compression is just .75cm

## Homework Equations

k=F/$$\Delta$$x
Power=Work/time

## The Attempt at a Solution

i thought the spring constant ,k, would be (mass of toy x 9.81)/(.015), but this is wrong.
then work would be, force(which i don't know how to find) x distance(.45).. but im not sure

Try Using this:

Elastic potential energy stored in wire or spring (Amount of work stored)

* W = ½keffX2, where X is the extension of spring

Okay, but I'm still not sure how to find the spring constant, was I on the right track by using F/$$\Delta$$x, where x=.015 m

and force is equal to .049x9.81

Okay so i figured out the constant by conservation of energy.
1/2kx2=mgh, solve for k
then for power p=w/t, i find t by finding$$\omega$$=sqrt. (k/m) then using that to find T, the period.
then work= 1/2kx2, so then i just divide the w/T, would this be correct?