Why sound travels faster on hot days

Sound propagation

As you can see, sound travels around four times as fast in water as it does in air. In wood, sound is around 16 times faster than in air.

Reflection of sound

When sound hits a solid object, e.g. a rock wall, the sound becomes reflected - he comes back and the sound can be heard again (a little quieter). The reflected sound is called echo designated.

Different materials reflect sound to different degrees. Hard, solid objects such as rocks, window panes, walls, tiles etc. reflect sound very well. Soft objects and surfaces such as carpets, sofas, curtains etc. reflect sound very poorly. The sound is practically swallowed (absorbed) by them.

Since we now have the Speed ​​of sound know, the distance to the rock face can be determined from the time between the emission of the sound and the arrival of the echo:

Task:

How far is a rock wall if the echo can be heard 6 seconds after the sound signal is sent out?

Solution:

As in the example above, the distance covered by the sound in 6 seconds is 2 kilometers. Since the sound takes the same time to reach the rock face as it does back from the rock face, the distance to the rock face is therefore exact half the size like the entire path traveled by sound.

So the distance to the rock face is 1 kilometer.

Echoes are generated in this way echo sounder used to determine sea depths: A ship becomes a Ultrasonic signal (Ultrasonic is sound that we cannot hear) emitted towards the sea floor and received again with an echo receiver. A measuring device is used to measure the exact time between sending and receiving the sound signal, and from this the depth of the sea is calculated.

Many animals orient themselves through echolocation

Dolphins orient themselves with the help of sound

Different animals orient themselves by sending out sound signals that are reflected by obstacles and received again.

For example, send Dolphins Clicks and whistles, but also inaudible to us Ultrasonic out.

Also Bats orient themselves in the dark with the help of ultrasonic signals.