A billiard ball is moving in the x direction at 30.0 cm/s and strikes another billiard ball moving in the y direction at 40.0 cm/s. As a result of the collision, the second ball moves at 50.0 cm/s, and the first ball stops. In what final direction does the second ball move? A) in the x direction B) at an angle of 45.0^o ccw from the x direction C) at an angle of 53.1^o ccw from the x direction D) Such a collision cannot happen.

Question

Quizplus · Accepted Answer

The final speed of the second ball is 50.0 cm/s, which is the resultant of its initial velocities in the x and y directions (30.0 cm/s and 40.0 cm/s respectively). Using the Pythagorean theorem, the angle can be calculated as tan^-1(40/30) = 53.1^o.

A Billiard Ball Is Moving in the X Direction at 30.0