Question

Two identical disc of equal radius and same mass are kept in contact in a frictionless table. A third ball of same mass but double radius strikes them symmetrically and comes to rest after the impact. What will be the cofficient of restitution?

Answer 1

Answer:

sorry I didn't know the answer

Answer 2

Answer:

Let

m

be mass of all three identical balls. Let the two stationary balls be positioned on the

y

-axis.

Let

u

ˆ

x

be velocity of striking ball.

As such initial momentum

=

m

u

ˆ

x

.

At the time of impact, which is given as symmetrical, the three centers of balls make an equilateral triangle.

By symmetry, after impact, both stationary balls will move with equal velocity along their respectively lines of impact which make an angle of

30

∘

with

x

-axis.