- #1
nothingsus
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Homework Statement
A stone is dropped in a well. The splash is heard 3s later. What is the depth of the well?
Homework Equations
constant acceleration equations
take speed of sound to be 343 m/s.
The Attempt at a Solution
For the stone:
u = 0
a = g
s = ut + 0.5at^2
subbing it all in you get t_stone = +sqrt(2s/g)
For the sound wave:
u = v = 343 m/s
v = s/t
subbing it all in you get
t_wave = s/343
(same distance traveled for stone and wave = s)
so you have t_stone + t_wave = 3
therefore
+sqrt(2s/g) + s/343 = 3
squaring both sides and moving over the constant
(s^2/343^2) + 2s/g - 9 = 0
solving this quadratic I get s = 44.02m or -24054m
The answer is 40.7m. Where did I go wrong?