Posted by Sandhu on .
A man drops a stone into a water well on his farm. He hears the sound of the splash 3.25 s later. The acceleration of gravity is 9.8 m/s2 and the speed of sound in air is 326 m/s. How deep is the well?

Physics 
lamiya,
100.3 meters, if I'm not mistaken..
Well deep = 326/3.25= ~100m 
Physics 
MathMate,
Denote the height by h, and the time for stone to descend t, we have the equation
h=ut+(1/2)gt&sp2;
where
u=0 m/s, initiial speed, and
g=acceleration due to gravity.
For the sound to return, we have
h=326 m/s*(3.25t)
Solve for h and t using the two equations.
You should have t=3.1 and h=47 m approximately 
Physics: corr 
MathMate,
h=ut+(1/2)gt²

Physics 
sandhu,
Thanks a lot

Physics 
Amy,
How exactly was h and t solved for?

Physics 
bianca,
Explain further pls