Six identical balls are lined up along a straight frictionless groove. Two similar balls moving with speed v along the groove collide elastically with this row on extreme left side end. Then :

Question

Six identical balls are lined up along a straight frictionless groove. Two similar balls moving with speed v along the groove collide elastically with this row on extreme left side end. Then : (A) One ball from the right end will move on with speed 2 v, all the other remains at rest. (B) Two balls from the extreme right will move on with speed v each and the remaining balls will be at rest. (C) All the balls will start moving to right with speed v /8 each. (D) All the six balls originally at rest will move on with speed v / 6 each and the two incident balls will come to rest.

Tardigrade Admin · Accepted Answer

For elastic head-on collision of equal masses, velocities get exchanged after the collision.

Q. Six identical balls are lined up along a straight frictionless groove. Two similar balls moving with speed $v$ along the groove collide elastically with this row on extreme left side end. Then :

One ball from the right end will move on with speed $2 v$ , all the other remains at rest.

Two balls from the extreme right will move on with speed $v$ each and the remaining balls will be at rest.

All the balls will start moving to right with speed $v /8$ each.

All the six balls originally at rest will move on with speed $v /6$ each and the two incident balls will come to rest.

For elastic head-on collision of equal masses, velocities get exchanged after the collision.

Q. Six identical balls are lined up along a straight frictionless groove. Two similar balls moving with speed v along the groove collide elastically with this row on extreme left side end. Then :

One ball from the right end will move on with speed 2v, all the other remains at rest.

Two balls from the extreme right will move on with speed v each and the remaining balls will be at rest.

All the balls will start moving to right with speed v/8 each.

All the six balls originally at rest will move on with speed v/6 each and the two incident balls will come to rest.

For elastic head-on collision of equal masses, velocities get exchanged after the collision.

Q. Six identical balls are lined up along a straight frictionless groove. Two similar balls moving with speed $v$ along the groove collide elastically with this row on extreme left side end. Then :

One ball from the right end will move on with speed $2 v$ , all the other remains at rest.

Two balls from the extreme right will move on with speed $v$ each and the remaining balls will be at rest.

All the balls will start moving to right with speed $v /8$ each.

All the six balls originally at rest will move on with speed $v /6$ each and the two incident balls will come to rest.