"I \"PHI-Ill. Homework problems #1 : A concave mirror has a focal length of 0.32m and a pencil is placed 0.2m in front of it. Find the image distance. #2: Now that you know the image distance of the mirror in #1, how much will the pencil be magnied? #3: A boy holds a toy soldier in from of a concave mirror. The focal length of the mirror is 0.45 m and the boy holds the toy soldier at a distance of 0.25m from the mirror. Find the image distance. #4: A friend is wearing a pair of mirrored sunglasses whose convex surface has a focal length of (-20.0) cm. If your face is 40.0 cm from the sunglasses, how far behind the sunglasses is your image