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1. Jan 11, 2006

StaticShock

What formula should I use for this question? I'm thinking hook's law, but It doesnt seem to fit.

A mass is attached to a spring that has a constant of 100 N/m. The mass vibrates with a frequency of 2 Hz.

I have to find the value of the mass and how far it streaches. I know I can use hook's law for the streaching part, but I am unsure of how to carry out this problem.

2. Jan 11, 2006

andrewchang

$$T = \frac {1}{f} = 2 \pi \sqrt {\frac {m}{k}}$$

3. Jan 11, 2006

StaticShock

Are you sure thats the right one? I mean, it looks as if its finding period not frequency. So wouldnt it be F=1/t= 1/2 pi Sqroot k over m?

4. Jan 11, 2006

andrewchang

that's just the general equation. it's up to you to do the algebra that will give you the value that you want.

5. Jan 11, 2006

StaticShock

well based on some information I found, the square root of the mass over K is equal to the equasion of L over g. If all things are reletive then, I should be able to switch it as i would when finding frequency.

Last edited: Jan 11, 2006
6. Jan 11, 2006

StaticShock

However, the second question may not have anything to do with hooke's law at all. It may just be F= 1 over 2pi Sqrt g over L

But I am unsure if g is to be used based on earth's speed of gravity or if I am on the right track at all.

7. Jan 11, 2006

andrewchang

why do you do this? the equation i gave you has frequency, mass, and the spring constant. you know two of these, so just solve for the mass.