# Mass dropped onto vertical spring what is the max compression?

1. Mar 1, 2013

### MathHelpa

1. The problem statement, all variables and given/known data
A mass m = 0.5 kg is dropped from a height of 1.5m above the end of an uncompressed vertical spring with k = 500 N/m. What is the maximum compression of the spring?

2. Relevant equations
f_sp = -kx
W_sp = 1/2 kx^2
W_nc = ΔK + ΔU
K = 1/2 mv^2
U = mgh
W = Fdcos∅
p = mv

3. The attempt at a solution
My friend and me were in different groups and they did the problem differently and came to a different answer. We set up ours as mg(h_0 + Δx) = 1/2hΔx^2 and came to a answer of .18 and rounded to .20 for Δx. My friend got much higher number so I was wondering what the answer really was and how to do it correctly if we are wrong.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Mar 1, 2013

### voko

What are 'h' and 'h_0' in you formula?

3. Mar 1, 2013

### ehild

You meant 1/2 kdx^2....