Science Project on “Finding the Direction of Sound”, Project Experiment Topics on Light, Sound, Maths, Optical Illusion for Class 8, 9, 10 and 12 Students.

Finding the Direction of Sound

Materials Required:

1. Seven friends
2. Fourteen pencils
3. A blindfold
4. A large bowl
5. Safety scissors
6. Paper

We have five senses to learn about our environment. Our ears are the wonderful organs that enable us to hear sounds. Since our ears are placed, one on either side of the head (instead of both on the same side), our brain can figure out from the signals, as to where a particular sound is coming from. Using your two ears, can you find your friends from the tapping sound they make?

With scissors, cut seven small pieces of paper. Write a number on each piece, from 1 to 7. Put all the pieces of paper in a large bowl. Gather seven friends. Give two pencils to each person. Tell each of your friends to pick a piece of paper from the bowl. Give a sheet of paper to one of the persons present. That person will keep a check on the number of guesses you get right. Stand in the middle of the room and have a friend blindfold you. Tell your friends to stand in a big circle around you, with you in the middle. One by one, have each friend tap two pencils together three times. The person who picked the paper marked “1”, goes first. After your friend taps the pencils together, point to where you think the sound is coming from. The person who is keeping track of whether your guesses are right or wrong, writes it down each time you point.

After the first person has tapped the pencils together and you have made your guess, the friend who has paper number “2” should repeat the same act as mentioned above. Have each friend take a turn, as you make your guesses, until all seven have gone. How many did you get right?

How far apart in distance, do the two sounds have to be, in order to be able to tell that they are coming from two different places? Have two friends stand close to each other and take turns tapping their pencils. Explain that sometimes the same person should take two turns, to see if you can tell that the sound has not moved. Try to tell the difference in a sound made, about two feet (60 cm) below and above your ear, when your friend is standing four feet (120 cm) behind you? Cover one ear and then try the tapping experiment with your seven friends again. How many do you think you will get right, using only one ear compared to, when you use both? What if you turn your head between taps?

The Speed of Sound

Quite like light, sound too travels in waves through the air. Sound waves travel by pushing the air thereby moving between alternate regions of high pressure air and regions of low pressure air. These changes in the air are created by the vibrating surface of the object that is producing the sound which in turn helps the sound to travel.

As soon as somebody speaks a few words, you can hear the sound. It seems that the sound has instantly moved from their mouth to our ears. This proves that sound reaches us instantly. This is so because the speed of sound is around 1,000 feet per second in air. This is why we are able to hear it quickly.

But believe it or not it is still approximately a million times slower than the speed of light. This is why we see things happen, at a distance, much before we actually hear the sound they produce.

For example during a thunderstorm, we are able to first see the flashes of lightning and the sound of the thunder clap follows a little later.