The depth of a well is 999 m. A man throws a stone in the well at a speed of 37 m/s. After how much time he will hear the sound of splash. Speed of sound is given as 333 m/s. The process is undergone in a gravity free space.
OPtion
1) 3 sec.
2) 10 sec.
3) 12 sec.
4) 15 sec.
5) 27 sec.
6) 30 sec.
7) 36 sec.
8) 45 sec.
9) 57 sec.
10) 60 sec.
Solution
time taken for the down motion of stone = 999/37 sec. = 27 sec.
time taken for the up motion of the sound = 999/333 sec. = 3 sec.
total sec. = 27 + 3 = 30