Question

7. Ball A with mass 0.85 kg is rolling at 3.5 m/s [N] when it collides with stationary Ball B with mass 1.15 kg. After the collision, Ball A is moving 2.4 m/s [N40ºW]. Find the velocity of Ball B after the collision.  

Answer 1

see the diagram :

given :

u = 3.5 m/s

mA = 0.85 kg

mB = 1.15 kg

v1 = 2.4 m/s

v2 = ?

suppose the shown direction in before collision is taken along +y -axis, then towards right perpendicular to y is +x-axis.

before collision : the mometum of the system is

after collision : the momentum of the system is

Applying conservation of Linear momentum of system :

=> v2 = .

.

therefore, the body B is moving with 1.67 m/s [N43.06oE] [asnwer]