A bubble of gas released at the bottom of a lake increases to four times its original volume when it reaches the surface. Assuming that atmospheric pressure is equivalent to the pressure exerted by a column of water 10 m high, what is the depth of the lake?

Options

A. 90 m
B. 10 m
C. 70 m
D. 80 m

Answer

C

Explanation

By using Boyle's law, `pxx8V=p_(1)xxV,8p=p_(1)`
`p_(1)` = atmosphere pressure+pressure due to water in lake
`:.` pressure of water in lake = 7p
Since, p=pressure exerted by 10 m of water, the depth of the lake=70 m.