Recall the amount of reflection is given as R Z1 Z2Z1 Z22

Recall the amount of reflection is given as:, R = (Z_1 - Z_2/Z_1 + Z_2)^2, where Z, is the impedance of the first medium, and Z_2 the impedance of the second. Note the impedance of air is only 410 Rayl, while that of water is 1,480,000 Rayl and glass is 13,000,000 Rayl. A dolphin is talking under water. How much of the sound is reflected as it hits a glass window? What percentage of the sound then actually is transmitted into the glass?

Solution

At the water-glass interface

Z1 = 1480000 Rl

Z2 = 13000000 Rl

Reflection R = (1480000 - 13000000)² /(1480000 + 13000000)² = 0.633

63.3 % of the sound is reflected.

b) percentage traansmitted = 100-63.3 = 36.7 % into the glass.