Suppose a small flashlight bulb is on the bottom of the bathtub of Problem 19, directly under the toy boat. When this bulb is lit and the ceiling light is turned off, how does the size of the shadow cast by the boat on the ceiling change when the water in the tub is replaced by a liquid in which the speed of light is \(\langle aangle\) faster than the speed of light in water and \((b)\) slower than the speed of light in water?

Data from Problem 19

The light bulb in a bathroom ceiling is directly over a toy boat floating in a bathtub filled with water to a depth \(x\). How does the shadow the boat casts on the bottom of the tub compare with the shadow it casts when the water is drained out and the boat is held the same distance \(x\) above the tub bottom? Treat the bulb as a point source.