Elastic Potential Energy and Energy Exchange

[Vegeance]

Homework Statement

A 3 kg ball is dropped from a height of 0.8 m above the top of the spring onto a vertical coiled spring sitting on the floor. The spring constant of the spring is 1200 N/m. Determine the maximum compression of the spring as the ball comes momentarily to rest before rising again. (0.22 m)

Homework Equations

1/2kx^2 (Spring Potential Energy as the area of kx graph)
Epg=mgh (Gravitational Potential Energy)
1/2mv^2 (Sum of energy -> Average kinetic energy of all particles -> velocity)

The Attempt at a Solution

I am not sure where I went wrong.
I meant b=-29.43.
x = 0.04905m

 

[ehild]

Decide from where do you count the height of the ball. If it is the upper end of the spring in equilibrium, then the final height is h₂=x₂ (a negative quantity).

ehild

 

[Vegeance]

Nevermind, I figured it out. It makes more sense for the gravitational energy h2 to be down upwards to the ball.

The first statement I made was false.