Topic 1 - Sound
What is Sound?
Sound can be described as a wave that transfers energy from one place to another.
Sound travels by making particles vibrate in a system of compressions (squashes) and rarefactions (stretches).
Wherever there are particles, sound can travel. This is why sound can travel through solids, liquids and gases.
In Physics, we say that sound waves are longitudinal waves. This means the vibrations are along the same direction of travel of the wave.
Sound can be described as a wave that transfers energy from one place to another.
Sound travels by making particles vibrate in a system of compressions (squashes) and rarefactions (stretches).
Wherever there are particles, sound can travel. This is why sound can travel through solids, liquids and gases.
In Physics, we say that sound waves are longitudinal waves. This means the vibrations are along the same direction of travel of the wave.
How can we hear?
Suggest how the following appliances could be adapted for people with hearing problems.
www.rnid.org.uk
www.deafcouncil.org.uk
www.royaldeaf.org.uk
- Public crossings at traffic lights
- A doorbell.
- A home telephone.
- A smoke alarm
www.rnid.org.uk
www.deafcouncil.org.uk
www.royaldeaf.org.uk
How Old are your Ears?
The Cathode Ray Oscilloscope (C.R.O)
The cathode ray oscilloscope is an instrument that allows sound waves to be displayed on a screen.
By looking at these waves, we can discuss how loud the sound is and what its pitch may be.
The Speed of Sound
Q. A bat sends out a high pitched squeak which echoes from objects in its path. This is how it knows that an object is there.
A moth is 51 metres from the bat. The bat sends out a squeak which echoes off the moth and returns 0.3 seconds later.
a) How far did the sound travel? (remember it had to travel to the moth and back again.)
b) Now calculate the speed of sound in air.
A moth is 51 metres from the bat. The bat sends out a squeak which echoes off the moth and returns 0.3 seconds later.
a) How far did the sound travel? (remember it had to travel to the moth and back again.)
b) Now calculate the speed of sound in air.
Sound in A Vacuum