Question

Oil explorers often set off explosives to make loud sounds, then listen for the echoes from underground oil deposits. Geologists suspect that there is oil under 515-m-deep Lake Physics. It's known that Lake Physics rests on top of solid granite. The speed of sound in water is 1480 m/s and the speed of sound in granite is 6000 m/s.

Part A

If an explosion is created at the surface of the lake, what time after the explosion do the explorers expect to hear an echo from the bottom of the lake?

Part B

In addition to the expected echo from the bottom of the lake, explorers also detect a faint echo 0.940 s after exploding the dynamite at the lake surface. If it's really oil, how deep will they have to drill through the granite to reach it?

Answer 1

since the tine spends m the wooder and er om 3 techo V 6ccom/s 6000 2