A stone is dropped into a lake from a tower 500 metre high. The sound of the splash will be heard by the man approximately after

Options

A. 11.5 seconds
B. 21 seconds
C. 10 seconds
D. 14 seconds

Answer

A

Explanation

Time taken by the stone to reach the lake
`t_(1)=sqrt((2h)/(g))=sqrt((2xx500)/(10))=10sec`
Time taken by sound to travel from lake to the man `t_(2)=(h)/(v)=(500)/(330)=1.5sec`
Time taken = `t_(1)+t_(2)=11.5` sec.