# Spring compression physics problem

1. Oct 4, 2009

### semc

A 1.5kg object is held 1.2m above a spring with force constant 320N/m. The object is dropped on the spring how far does the object compress the spring?

Alright so what i did was mgh=0.5kx^2 but the answer is different from the book. I guess is when the object touches the spring, its exerting a force downward to the spring due to gravity so i tried mg(h+x)=0.5kx^2 and solve the equation however this is wrong again.....Can someone tell me whats wrong?

2. Oct 4, 2009

### Staff: Mentor

Re: Springs!!!

That should work just fine. (It's a conservation of energy problem.) Why do you say it's wrong?

3. Oct 4, 2009

### semc

Re: Springs!!!

So you mean my second attempt is correct? Well, the answer i got is different from the one in my book.

4. Oct 4, 2009

### Staff: Mentor

Re: Springs!!!

Yes.
Show what you did and what the book says.

5. Oct 4, 2009

### semc

Re: Springs!!!

Hey doc my bad. The book uses g=10 instead of 9.81 hence the difference sorry about that. Thanks man!