# Homework Help: Will sound be affected by gravity in this simple problem?

1. Feb 20, 2012

### iJamJL

1. The problem statement, all variables and given/known data
Assume the air temperature is 10.8o C, and the speed of sound in air is 337.8 m/s. Suppose the lab floor is 2.61 m beneath the motion detector. If the detector produces a click, how long would it take before the echo returned?

2. Relevant equations
s=Vi*t + (.5)*(a)*(t^2)

3. The attempt at a solution
I just wanted to make sure I'm doing this correctly.

When going down:
distance = Vi(t) + (.5)*a(t^2)
2.61*2 (double distance) = 0 + [9.81*(t^2)] / 2
10.44 / 9.81 = t^2
t1 = 1.0316

2. Feb 20, 2012

### Pengwuino

For one, you need to give us a better idea of the problem as a lot of this seems vague.

Two, does that seem at all reasonable? Should sound take a whole second to travel only 2.6 meters?

3. Feb 20, 2012

### iJamJL

Found my mistake. I actually solved the answer correctly the first time (distance = v*t), but I accidentally input my answer incorrectly online. Woops