Waves
by: Erica Wolford
A wave is when energy travels
from one place to another in a quick pulse.
Wave Equation:
velocity
= frequency * wavelength
Wave Definitions:
·
Medium- the material a wave travels through
·
Frequency- number of waves made per second
·
Node- area of no apparent motion
·
Amplitude- strength of a wave
Types of Waves:
Ü
Transverse- energy and direction of the waves are perpendicular
Crest
Nodes
Trough
Ü
Compressional- energy and direction of the waves are parallel
Rarefractions compressions
Velocities of Waves:
v Electromagnetic
waves- waves that travel the speed of light (3*10^8 m/s)
Electromagnetic Spectrum:
1. Long waves
2. Medium waves
3. Short waves
------------BREAK---------
4. VHF (very high frequency)
5. FM
6. UHF (ultra high frequency)
v Mechanical
waves- any waves that travel slower than the speed of light
Example Problems:
1. A radio station operates on a frequency of 101.5 MHz. Solve for the wavelength of this station.
velocity
= frequency * wavelength
3*10^8 =
(101.5*10^6)*wavelength
wavelength = 2.96m
2. A short wave radio station has an antenna that uses a wavelength of 31.23 meters. Solve for the station’s frequency. (Answer in terms of Megahertz).
velocity =
frequency * wavelength
3*10^8 =
f(31.23)
f = 9.6MHz
3. A guitar string is 0.34 meters long. It makes ½ a wavelength when played. The speed of sound is 339.6 m/s. Solve for the pitch it makes.
velocity =
frequency * wavelength
339.6 =
f(0.34*2)
339.6 =
f(0.68)
f =
449.4Hz
