Periodic motion
Is motion of an object that regularly repeats – the object returns to a given position after a fixed time interval
Describing oscillatory motion
1 oscillation: is the movement of an object from a given position to another and back
Period: is the time taken for 1 oscillation (or cycle) and is measured in seconds
Frequency: is the number of oscillations or cycles per unit of time and is measured in hertz (1/s or s^-1)
Question: what is the F (frequency) and T (time) of a pendulum that swings 12 times in 6 seconds?
Answer Frequency = 12/6 = 2 Time (or period) = 6/12 = 0.5
Frequency and period are inversely proportionate
Amplitude and wave length
Types of waves
Characteristics of sound waves
Sound waves are a series of compressions (squashes) and rarefactions (stretches) that travel through air and other materials; this is cause by the vibration of particles.
In sound waves compressions are regions of high pressure and rarefactions are regions of low pressure. In a sound wave the air molecules move forwards and backwards; where they are squashed together, a compression results, where they are forced further apart, there is a rarefaction.
