1. The problem statement, all variables and given/known data A transparent cube with index of refraction n = 1.6 and side length a = 4.0 cm is free to rotate about an axis passing through its center. A laser beam is aimed at the cube. After passing through the cube the beam hits a screen on the other side forming a spot. The spot is displaced a distance y from the straight line path. The cube is then rotated at a constant angular velocity ω = 10 rad/s. As the cube rotates the spot moves. What is the speed of the spot at the instant that y = 0? (Answer 15 cm/s) 2. Relevant equations Snell's Law: n1*sin([itex]\theta[/itex]1)=n2*sin([itex]\theta[/itex]2) 3. The attempt at a solution I think I have to find y in terms of theta(from the center of the cube to the midpoint of edge of the cube), time t, side length a, and n. Then I could find dy/dt when y = 0. However I am unsure how to start or how I would use the angular velocity. Does the refracted laser inside the cube always hit the midpoint of the side like in the picture?