Conservation of energy/momentum

[chimez14]

Homework Statement

A proton with mass 1.59*10-27 kg is propelled at an initial speed of 3.49*105 m/s directly toward a uranium nucleus 4.97 m away. The proton is repelled by the uranium nucleus with a force of magnitude F = a/x2 where x is the separation between the two objects and a = 2.18 *10-26 Nm2. Assume that the uranium nucleus remains at rest. What is the speed of the proton when it is 8.60 *10-10 m from the nucleus?

Homework Equations

net force(F)=rate of change of momentum(dP/dt)
Total Energy before=Total Energy after
mathematically, E=kinetic energy(KE) before+potential energy(U) before=KE after + U after

The Attempt at a Solution

plugging in given values into the equations i think are relevant, but none of them get you any where..IS THERE AN EQUATION IM SUPPOSED TO USE?

 

[chimez14]

P.S initial speed=3.49*10^5 and so on

 

[physixguru]

Use simple Force equations.

 

[Doc Al]

Find the work done by the force. You'll have to integrate.