posted by jamie on .
Consider that a coin is dropped into a wishing well. You want to determine the depth of the well from the time t between releasing the coin and hearing it hit the bottom. Suppose that t=2.059 s and assume the speed of sound in air is 330 m/s. What is the depth of the well?
Can someone please help, I cant get the right answer.
What I did was (0.5)(-9.80)(2.059^2)= 20.77m
But it is not correct and when I incorporate 330 m/s it gives me really big value.
You did it incorrectly.
The coin hits the water, then the sound comes up. You are given the total time.
Let t be total time, t1 be the time to fall, so t-t1 is the time for the sound to come up.
set these equal, and solve for t1, then go back and solve for h.