Ok here is a little physics problem that I don’t remember how to solved. Help appreciated 
You have a line and a circle both have the same mass ‘‘m’’.
The line is not moving.
The circle is moving toward the line at an angle of 90 from the direction of the line.
The speed of the circle is ‘‘v’’.
The mass of the line is distributed uniformly amongst it and the size of the line is ‘‘L’’.
If the circle hit the line at one of it’s edge, what will happen?
The big problem is that the line can rotate. I know about stuff like moment of inertia but there is still something missing.
Is there a collision reaction similar to elastic collision for body that can rotate?