Question

A particle of mass m, makes a head-
on elastic collision with another
particle of mass m, at rest. m,
rebounds straight back with 4/9 of its
m.
initial kinetic energy. Then
is
m.
m
1
1)
2)
3
5​

Answer 1

Answer:

ANSWER

Given :         m1=m               m2=2m                       u2=0                    u1=u

Let the velocity of mass m after the collision be v1.

Using      v1=m1+m2(m1−em2)u1+(1+e)m2u2

v1=m+2m(m−1×2m)u+(1+1)2m(0)=3u

Thus final kinetic energy of m1,       E1′=21mv12=21m×9u2=181mu2

Initial kinetic energy of m1