Introducing the science of sound is more fun when your students can participate in hands-on experiments to illustrate the concepts. Below you will find two unique scientific experiments and activities to complement a classroom investigation of sound waves.
Objective: Defining sound
Sound is a form of energy propagated by the vibration of particles. When an object vibrates, the air in the vicinity also vibrates and thus a reaction process begins. This propagation of sound waves continues until it is unable to produce vibration in the surrounding medium. Anyone within the vibrating medium will be able to hear the sound.
Instruct the students to give examples for various sources of sound.
- Tuning Forks
- Small Paper pieces
- A large beaker
- Small Pebbles
- Begin your class by introducing the topic of ‘vibration’.
- Instruct them to closely watch the following experiment.
- Take the beaker and fill it with water.
- Put one pebble at the center of beaker. When water becomes still allow each student to add a pebble one after another.
- Now take a tuning fork and set it into vibration by hitting on desk. Let them listen the sound.
- Repeat the process, but this time let them feel the vibration of the fork.
- Turn the radio on and place paper pieces on its speaker. Direct your students to note down what they have seen.
Why do the paper pieces move?.
Analysis and conclusion:
On analyzing the result of the above three experiments children will arrive at a conclusion that sound causes vibration.
Objective: Sound travels through solid, liquid and gaseous medium.
Hypothesis: Sound can travel through any medium. Test the hypothesis using the following experiments.
- Two cups
- A long thread
- Glass tumbler (an empty fish tank is the best)
- Ice cubes
- Direct them to write down the medium, through which sound travels in each of the following experiments.
- Experiment 1. Let the students discuss how sound from the teacher reaches them.
- Experiment 2: Instruct your students to place their ears on the desk and gently tap the desk.
- Experiment 3: Make a small hole on each cup.
- Tie each end of the thread to each cup to construct a toy telephone.
- Get your students to an open space. The teacher will take one end of toy telephone, and let each of them to talk with you through the other end.
- Experiment 4: Take three glass bowls.
- Bring your students to one side of the empty fish tank. Instruct each of them to place their ears pressed to the fish tank.
- Gently tap on the other side.
- Now fill the tank with water.
- Repeat the procedure and let them hear the sound.
- Fill the tank with ice and repeat the above process.
Analysis and conclusion:
From the results, children should reach the conclusion that sound can travel through any medium.
For more experiments on the physics of sound waves, look to this article on understanding sound.