# Springs in harmonic motion

1. Sep 30, 2009

### kinetix

1. The problem statement, all variables and given/known data
"A certain spring with the mass of 10kg oscillates with a period of 10 seconds on the earth. What would be its period on a small moon, where the gravity is 1/16 as strong as on the earth?"

2. Relevant equations
I'm thinking I have to use the equation: T=1/2(pi)sqrt[L/g(1/16)]
but I am not sure as my professor will not answer a straight question of 'what formula should I use for this'.

3. The attempt at a solution
I ran into a problem here because the previous question asked almost the same thing but it was speaking of pendulums. I read somewhere that the mass of the spring is irrelevant in this problem but this is just confusing to me. I am only 2 weeks into this course about waves so I haven't had the time to adapt yet.
All help and suggestions are appreciated!
Thank You!
P. Ramos

2. Sep 30, 2009

### Delphi51

That formula for the period looks like the one for a pendulum, not a spring. But I think you have 1/2 where you should have 2.

You can find spring formulas at http://hyperphysics.phy-astr.gsu.edu/hbase/shm.html#c1
I see they give the formula for omega, which is 2(pi)f, and the frequency f is 1/period.
The spring constant k is a measure of how stiff the spring is.

The pendulum and the spring are quite different because gravity is the restoring force that pulls a pendulum back from the extremities of its oscillation. In the case of the spring, it is the spring itself that pulls its mass load back toward the equilibrium position.