Two solid balls A and B whose masses are 200 g and 400 g respectively, are moving in mutually opposite directions. If the velocity A is 0.3ms- 1 and both the balls come to rest after collision, then the velocity of the ball B is

Question

Two solid balls A and B whose masses are 200 g and 400 g respectively, are moving in mutually opposite directions. If the velocity A is 0.3ms- 1 and both the balls come to rest after collision, then the velocity of the ball B is (A) 0.15 m s- 1 (B) -0.15 m s- 1 (C) 1.5 m s- 1 (D) none of these

Tardigrade Admin · Accepted Answer

From the conservation of linear momentum Initial momentum = Final momentum 200(0.3)+400vB=0 vB=-0.15 m s- 1

Q. Two solid balls $A$ and $B$ whose masses are $200 g$ and $400 g$ respectively, are moving in mutually opposite directions. If the velocity $A$ is $0.3 m s^{- 1}$ and both the balls come to rest after collision, then the velocity of the ball $B$ is

$0.15 m s^{- 1}$

$- 0.15 m s^{- 1}$

$1.5 m s^{- 1}$

none of these

From the conservation of linear momentum
Initial momentum = Final momentum
$200 (0.3) + 400 v_{B} = 0$
$v_{B} = - 0.15 m s^{- 1}$

Q. Two solid balls A and B whose masses are 200g and 400g respectively, are moving in mutually opposite directions. If the velocity A is 0.3ms−1 and both the balls come to rest after collision, then the velocity of the ball B is

0.15ms−1

−0.15ms−1

1.5ms−1