P12.4 More about waves

Question 1

How can you use a loudspeaker to investigate sound waves?

Answer 1

You can observe the loudspeaker closely, you can see it vibrating.
It produces sound waves as it pushes the surrounding air backwards and forwards

Question 2

How can you test for that sound waves cannot travel through a vacuum?

Answer 2

Using an electric bell in in a bell jar

As the air is pumped out of the bell jar using a vacuum pump, the ringing sound fades away

Question 3

How can you use an oscillator to investigate waves?

Answer 3

Oscillator sends waves along the string. You can adjust the frequency of the oscillator until there is a single loop on the string
Note the frequency of the oscillator
Calculate wavelength
Calculate wave speed
Increase the frequency to obtain more loops on the string