Halliday, Resnick & Walker — Images: Problem 57

57 Figure 34-34 shows a small lightbulb suspended at distance \(d_1 = 300\text{ cm}\) above the surface of the water in a swimming pool where the water depth is \(d_2 = 200\text{ cm}\). The bottom of the pool is a large mirror. How far below the mirror surface is the image of the bulb? (Hint: Assume that the rays are close to a vertical axis through the bulb, and use the small-angle approximation in which \(\sin \theta \approx \tan \theta \approx \theta\).)