Collosions in 2-D
( A ball of mass m1 with initial velocity v1 strikes a ball of mass m2 initially at rest after collision, ball 1 moves with velocity v’ 1 and ball 2 moves with velocity v’ 2 with directions as shown in figure)
o With the above equations we have to solve the problem
Example: Two balls initially travelling along the x-axis with opposite velocities collide with each other obliquely, is it possible that they will move in the y-axis after collision?
Solution: Yes, it is possible, if the balls have same mass and travel with same speed. Initially their total momentum in x-direction was zero as their velocities were opposite; also in y-direction it is zero because they do not have velocity in that direction. Now after collision if their velocities are still equal and in opposite direction, the total momentum still remains zero.