Question

Two point charges `q_(1)` and `q_(2)` are released from rest in a gravity free hall when distance between them is `a`. Find the maximum speeds of charged particle. The mass of each charged particle is `m`.
A. `(q_(1)q_(2))/(4piepsilon_(0)a)`
B. `sqrt(((q_(1)q_(2)))/(4piepsilon_(0)ma)))`
C. `sqrt(((2q_(1)q_(2))/(4piepsilon_(0)ma)))`
D. none of these

Answer 1

(b) When separation between charges is infinitely large, potential energy is zero and kinetic energy of system is maximum. According to conservation principle of energy,

`1/2 mv_("max")^(2)+1/2mv_("max")^(2)=(q_(1)q_(2))/(4piepsilon_(0)a)` or `mv("max")^(2)=(q_(1)q_(2))/(4piepsilon_(0)a)`
`:. v_("max")=sqrt(((q_(1)q_(2))/(4piepsilon_(0)ma)))`