TWO SMALL PARTICLES OF EQUAL MASSES START MOVING IN OPP DIRN FROM POINT A IN A HORIZONTAL CIRCULAR ORBIT.THEIR TANGENTIAL VEL ARE V,2V.BETWEEN COLLISIONS,THE PARTICLES MOVE WITH CONSTANT SPEEDS .AFTER MAKING HOW MANY ELASTIC COLLISIONS OTHER THAN THAT AT A THESE TWO PARTICLES WILL AGAIN REACH POIMT A.

SIR.PLS EXPLAIN IN DETAIL AND THE CONCEPT U USED.

THKS

REGDS.

Dear vardaan

collision is perfectly elastic so after colision particle interchange their velocity.

particle having 2V velocity will cover 240 angel between successive colision and particle having V velocity will cover 120 angel between two succecssiive colision

le initially particle having 2V velocity is moving in anticlock wise direction.

angel covered by them is 

θ = 240 -120 +240 -120 +..........=n(360)    {anticlock wise direction is positive and clock wise direction is negative)

it will reach agian at staring point if angel covered by them is multiple of 360

θ = 240 -120 +240 -120 +..........=n(360)

     x*240  -y*120 = n*360

 now put value of x and y suck that it become multiple of 360  here y =x  or y=x-1

 let x=2 ,y=1

  2*240 - 1*120 =360

so total colision is (x+y) =3

if initial colision is not considered then total colision is =2

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