# Sound Question

#### sheri1987

1. The problem statement, all variables and given/known data

The distance between a loudspeaker and the left ear of a listener is 1.90 m.

(a) Calculate the time required for sound to travel this distance if the air temperature is 20°C.

2. Relevant equations
I am not sure, I tried looking in my text...but the only equation I could come up with is velocity = sqroot(ykT/m)
where y = specific heat, k is the Boltzmann constant, T is the given temp in K, and m is the distance..

3. The attempt at a solution

I have no idea where to even start, because only 2 things are known x in meters and the Temp 20 deg or 293 K. Can anyone help me out?

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#### mgb_phys

Homework Helper
You need the speed of sound in air. You can either look up the experimental real value or use the ideal gas approximation root(ykT/m) but here m is the molar mass of air not the distance!
You then use speed and distance to get the time.

#### sheri1987

what equation can you solve for time by having speed and distance?

#### mgb_phys

Homework Helper
what equation can you solve for time by having speed and distance?
Did you realy mean to write that!
What is the definition of speed?

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