You are visiting a friend in the hospital and realize someone is following you. When you look into one of the convex mirrors posted at a hallway intersection, our stalker appears to be 52.5 cm behind you.
a) If you hare 2.50 m from the mirror and the focal length of the mirror is 75.0 cm, how far is the stalker really from you?
b) What is the radius of curvature of the mirror?