Short-Question

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# Why does sound move more slowly at higher altitudes?

## Why does sound move more slowly at higher altitudes?

This is because pressure and density both contribute to sound velocity equally, and in an ideal gas the two effects cancel out, leaving only the effect of temperature. Sound usually travels more slowly with greater altitude, due to reduced temperature.

Why does sound travel faster at sea level?

The speed of sound will therefore be influenced by the pressure of the medium through which it is travelling. At sea level the air pressure is higher than high up on a mountain. Sound will travel faster at sea level where the air pressure is higher than it would at places high above sea level.

Does sound travel faster or slower at higher altitudes?

The speed of sound in the air mainly depends on temperature. At a typical sea level temperature, sound travels about 1,220 kilometers (760 miles) per hour. At high altitudes, where it is much colder, sound travels slower.

### Why do planes fly slower at higher altitudes?

As altitude increases, air density decreases, which decreases engine performance but gives it better fuel efficiency. However, less air density with high altitude does mean that the airplane has less wind resistance and drag, which partially offsets the decrease in engine performance.

How does altitude affect sound?

In the Earth’s atmosphere, the chief factor affecting the speed of sound is the temperature. Since temperature (and thus the speed of sound) decreases with increasing altitude up to 11 km, sound is refracted upward, away from listeners on the ground, creating an acoustic shadow at some distance from the source.

Why does sound travel slower?

Sound waves are made up of kinetic energy. It takes more energy to make large molecules vibrate than it does to make smaller molecules vibrate. Thus, sound will travel at a slower rate in the more dense object if they have the same elastic properties.

#### What happens to the speed of sound at higher altitude?

Since temperature (and thus the speed of sound) decreases with increasing altitude up to 11 km, sound is refracted upward, away from listeners on the ground, creating an acoustic shadow at some distance from the source. The decrease of the speed of sound with height is referred to as a negative sound speed gradient.

How does the speed of sound change with altitude?

At sea level, where the pressure is highest, the speed of sound is roughly 330 to 340 m/s (depends on the actual pressure and temperature). At higher altitudes, the pressure and temperature decrease, resulting in lower speeds of sound.

What’s the speed of sound at sea level?

It depends on your definition of higher altitude. The speed of sounds depends on both the pressure and temperature of the air. At sea level, where the pressure is highest, the speed of sound is roughly 330 to 340 m/s (depends on the actual pressure and temperature).

## Why is the speed of sound a function of temperature?

Since molecular speed in a gas is a direct function of average molecular kinetic energy and that is a direct function of temperature, the speed of sound in a gas will also be a function of temperature.