Homework Help: Different ways to calculate force, GPE

1. Jan 31, 2009

physicsman7

Different ways to calculate force, GPE......

1. The problem statement, all variables and given/known data

Different ways to calculate force,mass,Gravational Potienal Energy,seperation distance

2. Relevant equations

3. The attempt at a solution
Not sure how to find new ways to calculare these other than the already known formulas like
G(m1)(m2)/r^2

2. Jan 31, 2009

ritwik06

Re: Different ways to calculate force, GPE......

We shall be glad if you state clearly what exactly you want.

3. Feb 3, 2009

physicsman7

Re: Different ways to calculate force, GPE......

I want to know a diffrenet formula that can be used to caluclate those things

Different ways to calculate force,mass,Gravational Potienal Energy,seperation distance

4. Feb 3, 2009

v0id19

Re: Different ways to calculate force, GPE......

Well, all of these can be found many ways, and it's kind of unclear what you want.

For example:
$$\Sigma F = ma$$ gets you the force if you have mass and acceleration.
Fg=mg gives you the force on an object due to gravity.
$$E=\frac{k q_1 q_2}{r^2}$$ gives you the electric field (which is a force)
$$F_g=\frac{g M m}{r^2}$$ is the general force of gravity.
and there are many more.

Mass can be calculated from lots of things, assuming you know other variables--kinetic energy, certain potential energies, certain forces, net force, etc.

GPE can be found using the generic equation $$U_g=-\frac{g M m}{r}$$, by total energy minus everything that's not GPE, Ug=mgh, integrating force, etc

Separation distance (if I am interpreting it correctly) can be found by knowing the result of most of the equations I have already listed and solving for r and other ways.

Last edited: Feb 3, 2009
5. Feb 5, 2009

physicsman7

Re: Different ways to calculate force, GPE......

thanks, sorry im also a little unclear withe question is as well it wants to know new ways to calculate all those things thats all it says but thanks for the help