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 .