Question

You wish to use a spring that has a constant of 25N/m to launch a 25.0g object. If the spring is initially compressed 5.0cm before launching the projectile, what is the maximum height the object will attain.

Answer 1

by energy conservation:

$\frac{kx^2}{2}=mgh$

then, the maximum height the object will attain:

$h=\frac{kx^2}{2mg}=\frac{25\cdot 0.05^2}{2\cdot 25\cdot10^{-3}\cdot 9.8}=0.13$ m