# Ball and Spring mechanics

**Classical Mechanics**Level 2

A ball with a mass (\(m\)) of \(30\text{ kg}\), is placed on top of a frictionless hill at a height (\(h\)) of \(5\text{ m}\). How much will the spring at the bottom of the hill be displaced in order to stop the ball if the spring constant (\(k\)) is \(30 \frac{N}{m}\)?

**Note**: \[Assume \space g = 10 \frac{m}{s^2} \\ U_{spring} = \frac{1}{2} k x^2 \\ U_{potential} = mgh \]