Billiard ball A, mass 0.17 kg, is moving due east with a velocity of 4.0 m/s. It strikes stationary billiard ball B, which has the same mass. After the collision, ball A moves
at an angle of 30° north of east with a velocity of 3.5 m/s. Ball B moves at an
angle of 60° south of east. What is the speed of ball B?
a
2 m/s
b
8 m/s
С
10 m/s
d
5 m/s