A 42.5 g marble is fired vertically upward using a spring gun. The spring must be compressed 7.0 cm if the marble is to reach a target 27.0 m above the gun. What is the change in gravitational energy of the marble during its ascent?

Answer 1

Potential Energy = Kinetic Energy
m*g*h = m/2*v^2
0.0425*9.8*27 = 0.02125*v^2
Solve for v^2.

Kinetic Energy (marble) = Potential Energy (spring)
m/2*v^2 = k/2*y^2
0.02125*v^2 = k/2*0.0049^2
Solve for k.

Change in gravitational energy is equal to m*g*h.