Question

Two identical balls, one moves with 12 m/s and
second is at rest, collides elastically. After collision
velocity of second and first ball will be :
(1) 6m/s, 6m/s
(2) 12m/s, 12m/s
(3) 12m/s, Om/s (4) 0m/s, 12m/s​

Answer 1

Answer:

$m_1v_1+m_2v_2=(m_1+m_2)v$

Explanation:

We have given that there are two identical balls so there mass will be same

Let mass of ball 1 $m_1=m$ so mass of ball 2 will also be $m_2=m$

We have given velocity of ball 1 $v_1=12m/sec$

And ball 2 is at rest so velocity of ball 2 $v_2=0m/sec$

Now according to conservation of momentum

Initial momentum = final momentum

So $m_1v_1+m_2v_2=(m_1+m_2)v$

$m\times 12+m\times 0=(m+m)v$

$12m=2mv$

v = 6 m/sec

So velocity of both the ball will be 6 m/sec

So option (1) will be correct option