Question

A ball with a mass of `140` `g` is projected vertically by a spring loaded contraption. The spring in the contraption has a spring constant of `42` `kgs^-2` and was compressed by `5/3` `m` when the ball was released. How high will the ball go?

Answer 1

The spring potential energy is `E_p=1/2kx^2=1/2xx42xx(5/3)^2=58.3` `J`
This energy will be converted to gravitational potential energy, `E_p=mgh`. Rearranging: `h=E_p/(mg)=58.3/(0.14xx9.8)=42.5` `m` (remembering to convert the mass to kg, the SI unit)