Two billiard balls of equal mass move at right angles and meet at the origin of an xy coordinate system. Initially ball A is moving upward along the y axis at 1.5 m/s, and ball B is moving to the right along the x axis with speed 4.0 m/s. After the collision (assumed elastic), the second ball is moving along the positive y axis (see figure).
(a) What is the final direction of ball A?
______° (counterclockwise from the +x axis is positive)
(b) What are their two speeds?
v'A =____ m/s
v'B =____ m/s
The Attempt at a Solution
b) I am not sure where to begin....I know that KE is conserved, so momentum before is equal to momentum after.