Particle `A` having positive charges is moving directly head -on to wards initially stationary positively charged particle ` B`. At the instant when `A` and `B` are closest together .

Options

A. the momenta of A and B must equal
B. the velocities of A and B must qual
C. B would have gained less kinetic energy that A would have lost
D. B would have gained the same momentum of A would have lost.

Answer

B, C, D

Explanation

No net external force =, hance, momentum will conserved.
(loss in momentum of A) = (gain in momentum of B)
for `S_(rel)` to be minimum, `(d)/(dt)(S_(rel))=0`
i.e. `v_(rel)=0orv=v'`