revision: Physics - Topic 3

3a) Units 

3.1 - use the following units: degree (˚), hertz (Hz), meter (m), meter/second (m/s), second (s)

degree (˚) - angles
hertz (Hz) - frequency (number of waves per second)
meter (m) - distance or length
meter/second (m/s) - speed or velocity
second (s) - time

3b) Properties of Waves

3.2 - understand the difference between longitudinal and transverse waves and describe experiments to show longitudinal and transverse waves, for example, ropes, springs and water.

Transverse waves can be produced in ropes and springs. Longitudinal waves move in a parallel direction to it's length.

Transverse - when the displacement of a wave is perpendicular to the direction of the wave.
Longitudinal - when the displacement of a wave is the same as the direction of the wave.

(REMEMBER -> LONGitudinal so the displacement is long - parallel to the LENGTH of the wave.)

3.3 - define amplitude, frequency, wavelength and period of a wave

amplitude - the maximum displacement of a wave.
frequency - the number of cycles per second.
wavelength - the distance between the peak of a wave and the next peak
period - the time taken for one complete cycle of a wave.

(REMEMBER -> A period of time...period is a time measurement. Don't confuse it with wavelength!!)

3.4 - understand that waves transfer energy and information without transferring matter

Ummm...exactly what it says?

Waves can transfer energy and information from one place to another. Also, the energy and information transferred by the wave is done so without transferring any matter.

3.5 - know and use the relationship between the speed, frequency and wavelength of a wave:

wave speed = frequency x wavelength
v = f x λ

(REMEMBER -> v = f x λ, I remember it by saying We = famous people...we are famous people cuz f is for famous and λ looks like the Chinese character for person.)

3.6 - use the relationship between frequency and time period:

frequency = 1/time period
f = 1/T

(REMEMBER -> Well, I think only my friends will get this but... frequency = 1/wings ^^)

3.7 - use the above relationships in different contexts including sound waves and electromagnetic waves.

3.8 - understand that waves can be diffracted when they pass an edge

All kinds of waves can be diffracted.