Question

three idntical spherical ball A, B,C are placed on a table as shown in the figure along a straight line . B and C are at rest initilly . the ball A hits B head -on with a speed of 10 ms ${}^{-1}$.then after all collision s( assumed to be elastic )A and B are brought to rest and C takes off with a velocity of

• A. $5m{s}^{-1}$
• B. $10m{s}^{-1}$
• C. $2.5m{s}^{-1}$
• D. $7.5m{s}^{-1}$

Answer 1

The correct option is B $10m{s}^{-1}$

In elastic collision

Applying conservation of momentum

m( 10) $=m\left(v_1\right)$

$v_1=10$

$v_2=$0

then

$m{v}_1=mv$

$v=10$

so velocity of c spherical ball

$=10m/s$