- #1

issacnewton

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- Homework Statement
- A proton of mass ##m## and charge ##e## is projected from a very large distance towards an ##\alpha## particle with velocity ##v##. Initially, ##\alpha## particle is at rest, but it is free to move. If gravity is neglected, then the minimum separation along the straight line of their motion will be

A. ##e^2/4\pi\varepsilon_0 m v^2##

B. ##5e^2/4\pi\varepsilon_0 m v^2##

C. ##2e^2/4\pi\varepsilon_0 m v^2##

D. ##4e^2/4\pi\varepsilon_0 m v^2##

- Relevant Equations
- Coulomb's law of interaction between charged particles

Proton is going towards the ##\alpha## particle. So, I am thinking of using the conservation of energy as the initial kinetic energy of the proton is known and initial interaction potential energy is zero. But, we don't know the kinetic energies of proton and ##\alpha## particle when they are at their minimum separation. So, what could be possible approach here ?

Thanks

Thanks