9. The focal length of a camera lens is 20.0 cm. How far from the lens should the subject for the ph
問題詳情
9. The focal length of a camera lens is 20.0 cm. How far from the lens should the subject for the photo be if the lens is 20.5 cmfrom the film? (A)8.20 m (B)4.10 m (C) 2.10 m (D) 6.30 m (E) 10.0 m