What is the speed of sound in neon?

Question

A 530-Hz sound travels through pure neon. The wavelength of the sound is measured to be 0.82 m.

 What is the speed of sound in neon?

Answer 1

Okay.

So wavelength equals meters/wave

Speed equals meters/second

Frequency equals waves/second

The basic equation is

Wavelength=speed/frequency

Because this allows us to take the meters/second unit, divide it by the waves/second unit, and have the seconds cancel out and give us meters/wave.

Usually, the speed of sound is treated as a constant, and we're solving for frequency or wavelength. However, in this case, we're experimentally determining it by measuring the sound waves directly.

So if you multiply both sides by frequency, you get instead

Frequency×wavelength=speed

Because the waves/second times meters/wave units times each other causes "waves" to cancel out, giving us just meters/second.

The answer becomes 434.6 meters per second. Incidentally, this means the Neon gas is at zero degrees Celsius, by the way.

Answer 2

v = fλ = 530 Hz·0.82 m = 434.6 m/s

Answer 3

Speed, c, is defined as the product of the wavelength, λ, and the frequency, f:

c = λ · f

Therefore, it is just a matter of plugging in the values given:

1. c = λ · f
2. c = ( 0.82 m. ) · ( 530 Hz. )
3. 434.6 m./s.
4. 430 m./s. (two significant figures only!)