Part C Now, grab Tracker’s protractor tool (the green angle in the video frame) and measure the angle of incidence and the angle of refraction for the frame numbers specified in the table below. Hints: To advance the video a frame at a time, use the step buttons on the right. Position the vertex of the protractor exactly at the origin of the coordinate axis. Move the arms of the protractor so that one arm is on the vertical axis (above or below, as appropriate) and the other on the light ray.
