Posted by Katie on .
While stationary on a boat you are measuring the time it takes for the coin to leave your hand and hit the water.In order to measure that time you are tuned to the sound of the coin hitting the water. You know that it takes 5.5 seconds for the coin to leave your hand and hit the water but the timer that you are using shows 6 seconds. What is the distance between your hand and the water surface? What is the speed of sound in this case?
The extra 0.5 seconds is the time it takes for the sound of the splash to reach you.
The height of the hand above the water surface is
(1/2)gt^2 = (4.9)(5.5)^2 = 148 m.
The speed of sound is 148/0.5 = 296 m/s