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/m², p=1030kg/m', and for air, y = 14, and T= 270°K).

Fig: 1

Fig: 2