1. The problem statement, all variables and given/known data Alright apologies I could not attach an image due to my inexperience of this but its simple to imagine. Imagine a stick which can rotate about the centre of its axis, perpendicular to its length. I.e the ends can rotate freely in a clockwise, or anti clockwise manner. Now imagine a ball travelling right to left, and hits the top of the stick. At the same time, a ball travelling left to right hits the bottom of the stick. Lets say the balls have same mass and same velocity. The stick will rotate anti clockwise. The balls will have equal and opposite LINEAR momentum, but do they have equal and opposite angular momentum relative to the rotational axis of the stick? angular momentum is L = r x mv = Iw. For an object travelling in linear motion relative to some origin to find the angular momentum we use L = r x mV. I thought mV was just its linear momentum, so it should be opposite, but then again both the balls are helping the stick rotate in the same direction, so does that mean they have the same direction in terms of angular momentum?