Waves exercises

Waves

A wave is a disturbance that carries energy from one place to another.

Matter is NOT carried with the wave! A wave can move through matter (a “medium”). If it must have a medium, it is called mechanical wave. If it can travel without a medium (such as in space), it is called electromagnetic wave.

Wave Types

1.      Transversal waves: Waves in which the medium moves at right angles to the wave direction.

Parts of a transverse wave:

Crest: the highest point of the wave

trough: the lowest point of the wave

2.      Compressional (longitudinal) wave: Waves in which the medium moves back and forth in the same direction as the wave.

Wave properties depend on what type of energy makes the wave.

1.      Wavelenght: The distance between one point on a wave and the exact same place on the next wave.

2.      Frequency: How many waves go past a point in a second; measured in hertz (Hz). The higher the frequency, the more energy in the wave.

3.      Amplitude: How far the medium (crests and troughs, or compressions and rarefactions) moves from the line of origin (the place the medium is when not moving). The more energy a wave carries, the bigger its amplitude.

4.      Wave speed: Depends on the medium the wave is traveling in. This varies in solids, liquids and gases.

            Equation for calculating wave speed:

            wave speed = wavelencht (in m) x frequency (in Hz)

Problem:

If a wave has a wavelength of 2 m and a frequency of 500 Hz, what is its speed? Answer: wave speed  =1.000 m / second