What is speed of sound

The above equation is useful for solving mathematical problems related to the speed, frequency and wavelength relationship. However, one important misconception could be conveyed by the equation. Even though wave speed is calculated using the frequency and the wavelength, the wave speed is not dependent upon these quantities. An alteration in wavelength does not affect i. Rather, an alteration in wavelength affects the frequency in an inverse manner.

A doubling of the wavelength results in a halving of the frequency; yet the wave speed is not changed. The speed of a sound wave depends on the properties of the medium through which it moves and the only way to change the speed is to change the properties of the medium.

An automatic focus camera is able to focus on objects by use of an ultrasonic sound wave. The camera sends out sound waves that reflect off distant objects and return to the camera. A sensor detects the time it takes for the waves to return and then determines the distance an object is from the camera.

Use 0. On a hot summer day, a pesky little mosquito produced its warning sound near your ear. The sound is produced by the beating of its wings at a rate of about wing beats per second.

Substitute and solve. Doubling the frequency will halve the wavelength; speed is unaffected by the alteration in the frequency. The speed of a wave depends upon the properties of the medium. Playing middle C on the piano keyboard produces a sound with a frequency of Hz. Most people can detect frequencies as high as 20 Hz. An elephant produces a 10 Hz sound wave. The speed of sound in air is dependent upon the temperature of air. The dependence is expressed by the equation:.

Miles Tugo is camping in Glacier National Park. In the midst of a glacier canyon, he makes a loud holler. He hears an echo 1. The air temperature is 20 degrees C. How far away are the canyon walls? Two sound waves are traveling through a container of unknown gas. Wave A has a wavelength of 1.

Wave B has a wavelength of 3. The speed of a wave does not depend upon its wavelength, but rather upon the properties of the medium. The medium has not changed, so neither has the speed. Since Wave B has three times the wavelength of Wave A, it must have one-third the frequency. Frequency and wavelength are inversely related. Physics Tutorial. My Cart Subscription Selection.

The speed of sound in air depends on the type of gas and the temperature of the gas. On Earth, the atmosphere is composed of mostly diatomic nitrogen and oxygen, and the temperature depends on the altitude in a rather complex way.

Scientists and engineers have created a mathematical model of the atmosphere to help them account for the changing effects of temperature with altitude. Mars also has an atmosphere composed of mostly carbon dioxide. There is a similar mathematical model of the Martian atmosphere. We have created an atmospheric calculator to let you study the variation of sound speed with planet and altitude. Here's a JavaScript program to calculate speed of sound and Mach number for different planets, altitudes, and speed.

You can use this calculator to determine the Mach number of a rocket at a given speed and altitude on Earth or Mars. This page shows an interactive Java applet which calculates the speed of sound and the mach number for an input velocity and altitude.

To change input values, click on the input box black on white , backspace over the input value, type in your new value, and hit the Enter key on the keyboard this sends your new value to the program. You will see the output boxes yellow on black change value. You can use either English or Metric units and you can input either the Mach number or the speed by using the menu buttons. Just click on the menu button and click on your selection. There is a sleek version of this program for experienced users who do not need these instructions.

Well, as you get higher in the altitude up to a point , the temperature decreases. The pressure and the density of air also decrease. The effects due to pressure and density essentially negate each other. Like I said, this over simplifies the whole issue. The Wikipedia page on the speed of sound has a lot more detail if you are interested. If you put this together, you can get a plot of the speed of sound as a function of altitude.

Oh sure, it will change with weather and stuff, but still you can get a pretty basic model. Here is a plot of the speed of sound at different heights above sea level. Just from this data, you can see that Felix Baumgartner did indeed fall faster than the speed of sound. However, the question doesn't really make sense. Did he fall faster than the speed of sound at sea level?

Was he also going faster than the speed of sound for the altitude he was at? Well, it makes logical sense that if the speed of sound is greatest at sea level and he went faster than the speed of sound he would be going faster than the locals speed of sound. I don't know if "local speed of sound" is an official term, but I like it.

I am using it to mean the speed of sound at the current altitude. Here is a plot of the speed of Felix as he falls along with the plot of the local speed of sound at that same time. You will notice that from this numerical calculation, Felix was going faster than the local speed of sound for about 45 seconds.

I guess I was right at least according to Wikipedia. It has the definition of Mach number as the ratio of the speed of an object to the local speed of sound. Here is a plot of the speed of Felix as a function of altitude in terms of the Mach number again, this is based on my not so perfect model. From this, he had a maximum speed of Mach 1. Of course this is very dependent on the actual speed of sound at that altitude. If the model is off a little bit on the speed of Felix as well as the speed of sound at that altitude both using simple models , that could explain the discrepancy.

Either way, there seems to be little doubt he went faster than the speed of sound. However, he didn't break the speed of light. I have trouble believing this is real, but I couldn't find evidence that it was fake. In case you didn't click the image, it shows Felix Baumgartner after he stabilized his fall.

The caption reads and I kid you not :. Have you ever seen lightning and heard thunder? Do you hear them at the same time? You know why? Because the light from the event travels so much faster than the sound.

The speed of light is crazy fast and you can't really go faster than it anyway. Let's start with Felix's post jump press conference. Here is what he said full transcript available :.