Objective: Defining sound
Children know what is sound, but they don’t know the science behind sound. Sound is a form of energy propagated by the vibration of particles. When an object vibrates, the air in the vicinity also s vibrates and thus a chain process begins. This propagation of sound waves continues until it is unable to produce vibration in the surrounding medium. Those persons who are within this vibrating medium can perceive sound.
Instruct the students to give examples for various sources of sound and physics sound waves.
Materials:
- Tuning Forks
- Radio
- Small Paper pieces
- A large beaker
- Water
- Small Pebbles
Procedure:
- Begin your class by introducing your students 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.
Question:
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.
