4. A wave in a ripple tank passes from a deep to a shallow region with 8, = 60 and 82 = 45. Calculate the ratios in the two media of (a) the wavelengths, (b) the speeds, and (c) the frequencies. 40. 5. Water waves travelling at a speed of 28 cm/s enter deeper water at 0 E Determine the speed in the deeper water if 0 = 46. 6. A 10.0-Hz water wave travels from deep water, where its speed is 38.0 cm/s, to shallow water, where its speed is 28.0 cm/s and 0,= 30. Find (a) the index of refraction, (b) the wavelengths in the two media, and (c) the angle of refraction in the shallow water. I