3. A noise created by small earthquake at a depth of 1200m in the ocean propagates upward and eventually reaches a bird flying above, at an altitude of 400m. Calculate

how long it takes for the noise to reach the bird. For the seawater use E 2.34 x 10°N/m, p=1030kg/m, and for air, y 1.4, and T= 270 K).