Which glass is used in astrology? what is its focal length?

Convex lens is used in astrology. "For a thin lens in air, the focal length is the distance from the center of the lens to the principal foci (or focal points) of the lens. For a converging lens (for example a convex lens), the focal length is positive, and is the distance at which a beam of collimated light will be focused to a single spot."

Explanation:

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray

the force represented by vector a is normal force. if the hockey puck is moving to the right, when it is hit with a significant force by the hockey stick the puck will move off in a different direction. correct on edge.