Question

Imagine a superfast fish that is able to swim faster than the speed of sound in water. Would this fish produce a “sonic boom”?

Use the concepts from this module to explain why flying bees buzz.

If the handle of a tuning fork were to be handled firmly against a table, would the sound from the tuning fork change? If so, what would change?

The strings of a harp have different length in order to produce different notes. However, given that the strings in a guitar have all the same length, how are the different notes produced?

Answer 1

1. Yes, there will definitely be a sonic boom if the fish swims at faster than the speed of sound in water. Water can transmit sound waves even though it is relatively incompressible as compared to air. Therefore it will exhibit a cone shaped sonic boom. As we know, the sonic boom is emitted from the leading edge of the fish that is moving through the water at a speed fastern than that of sound. The thing to remember here is that the speed of sound is different in water than in air. The speed of sound in air is 1236 km/hr (at a temperature of 20 ^oC and pressure of 1 atm). The speed of sound in water is 5336 km/hr.

2. There are two reasons for the buzzing of bees. The firt is the rapid beats of the wings. This creates wind vibrations which we hear as a buzz. The second reason is that some bees vibrate their thorax and wing muscles while on a flower. This is done to get the pollen off the flower's anthers onto the bee's body.

3. Yes, The sound of tuning fork will become louder if held against a table firmly. The entire table will now vibrate. The greater is the surface area, the more air molecules will vibrate. Sine the table has a greater surface area so the sound will get louder.

4. The frequency of vibration can be changed by changing the tension in the string using tuning pegs. When we tune up, the string gets tighter resulting in a higher pitch. The frequency also depends upon the length of the string. We can change this by pushing the string tightly against the finger board with the left hand finger hence shortening the string to the desired level.