Three identical discs, A, B and C rest on a smooth horizontal plane as shown in figure. The disc A is set in motion with velocity v along the perpendicular bisector of the line BC joining the centres of the stationary discs. The distance BC between the centre of stationary discs B and C is n times the diameter .d. of each disc. At what value of n will the disc A recoil, stop and move on after elastic collision?

Three identical discs, A, B and C rest on a smooth horizontal plane as

1.	Three identical discs, A, B and C rest on a smooth horizontal plane as shown in figure. The disc A is set in motion with velocity v along the perpendicular bisector of the line BC joining the centres of the stationary discs. The distance BC between the centre of stationary discs B and C is n times the diameter .d. of each disc. At what value of n will the disc A recoil, stop and move on after elastic collision?
Answer» ANSWER :`N LE SQRT2 , n = sqrt2 n GT sqrt2`