The equation you are give in your exam is
'SPEED = FREQUENCY x WAVELENGTH'.
'SPEED = FREQUENCY x WAVELENGTH'.
The first way is too use the triangle above. To use it you simply cover up the part you want the answer for, you are then left with a simple equation which you put in your numbers and easily work out.
The second way is the '6,3,2' method, which is great if you know how to do it.
You place the numbers in order over the equation you are given, eg. 6, over 'speed' and 3, over 'frequency' etc.
Once you have done this you simply choose the number/part you want and work out the simple maths equation and turn it into a rearranged formula.
You place the numbers in order over the equation you are given, eg. 6, over 'speed' and 3, over 'frequency' etc.
Once you have done this you simply choose the number/part you want and work out the simple maths equation and turn it into a rearranged formula.
Examples
Speed = Frequency x Wavelength = 10 Hz x 2 m = 20 m/s
Frequency = Speed / Wavelength = 200 m/s / 50 m = 4 Hz
Wavelength = Speed / Frequency = 100 m/s / 4 Hz = 25 m
Speed = Frequency x Wavelength = 4 Hz x 25 m = 100 m/s
Wavelength = Speed / Frequency = 1000 m/s / 200 Hz = 5 m
Frequency = Speed / Wavelength = 300 m/s / 30 m = 10 Hz
Wavelength = Speed / Frequency = 2000 m/s / 2 Hz = 1000 m
The link between Time Period & Frequency
Frequency = 1 / Time Period
OR
Time Period = 1 / Frequency
OR
Time Period = 1 / Frequency
5 waves in 2 seconds
2.5 waves in 1 second = 2.5 Hz
2.5 waves in 1 second = 2.5 Hz
Frequency = 4 Hz
Time Period = 0.25 s
OR
1/4 s
Time Period = 0.25 s
OR
1/4 s