I need a little info please

1. Aug 30, 2006

bucky1andonly

is there any formulas for a spring, or any way at all to calculate the weight needed to compress a spring, or do you just have to experiment

2. Aug 30, 2006

quasar987

Mmh the law is "you have to exert a constant force of kx to maintain the spring stretched a distance x from its position of equilibrium", where k is the spring constant. But ultimately, you have to find k experimentally.

3. Aug 30, 2006

WhyIsItSo

quasar987 is correct; k can only be determined experimetally. Once you have that:

A simple form of Hooke's law
$$F=-kx$$
F = force. k = spring constant. x = displacement from relaxed (not stretched or compressed). Note the right side is negative to denote "equal but opposite".

Also:
$$PE = \frac{1}{2}kx^2$$.

4. Aug 31, 2006

Staff: Mentor

The negative sign in Hooke's law indicates that the direction of the restoring force is opposite to the displacement from the unstretched position. For example: Displace the end of the spring to the right, the spring force acts to the left.

5. Aug 31, 2006

Staff: Mentor

...if you don't have K, though, you can still calculate it from the properties of the material and shape of the spring.

6. Aug 31, 2006

bucky1andonly

thx, that helped a lot

7. Sep 1, 2006

Hootenanny

Staff Emeritus