What is the formula for calculating velocity in a classical potential?

[transgalactic]

http://img150.imageshack.us/img150/6822/15938367dw2.th.gif

 

[Alewhey]

Well it looks like the question is about a classical potential.

If a particle has an energy E and is moving in a potential V, then we have

Kinetic Energy = (E - V) = $$\frac{1}{2}mv^{2}$$

Then solve for v:

$$v = \sqrt{\frac{2(E-V)}{m}}$$