A vertical spring with constant 200 N/m has a light platform on its top. When a 500 g mass is kept on the platform spring compresses 2.5 cm. Mass is now pushed down 7.50 cm further and released. How far above later position will the mass fly?
When the external force is removed after the push, the mass gets detached when spring obtain its natural length and say, mass m rises h height from the pushed position.
Loss in potential energy of spring = Gain in gravitational potential energy.
h = 0.2 m