Question

Describe a simple experiment to determine the speed of sound in air. What approximation is made in the method described by you ?

Answer 1

You can perform so many experiment to find the speed of sound in air.
One of the simple experiment is as follows:

• For this experiment you need a cracker, stopwatch, meter tape and help of one of your friend.
• Choose two spots. Tell your friend to stand at one of the spot with the cracker and pick the other spot for yourself at a distance of 300 m from the first spot such that you can see the cracker. Performing the experiment is dusk will help you to view the cracking of cracker easily.
• The distance should be measured accurately by using the meter tape.
• Now signal your friend to burn the cracker.
• Once you see the flash of explosion of cracker, start the stop watch.
• Once you hear the sound of explosion of cracker, stop the stop watch.
• Now you have the time taken by sound to cover 100 m.
• So the velocity of sound will be simply distance divided by time.
• Perform this experiment few more times to get better results.

Approximation:

• As speed of light is very much greater than the speed of sound so, it is approximated that the light instantly reaches to us when the cracker explodes.
• The wind effects the speed of sound but here the speed of wind is neglected.
• As the temperature also, affects the speed of sound but here it has not been considered also.