Oscillations and Waves - Wave Properties

Question 1

waves

Answer 1

• There are a number of measurable properties we use to describe waves. First, we have to identify some points on the wave. The highest point on a wave is called a “crest.” A typical wave has many crests as the wave goes up and down repeatedly. The lowest point on a wave is called a “trough.”
• The distance from one crest of a wave to the next is called the “wavelength” of the wave. The symbol is the Greek letter lambda, , and it is measured in meters. It is also the distance between two troughs.
  The Period T of a wave is how much time it takes the wave to move one wavelength. In that time, an individual oscillator in the wave goes through one oscillation, as in SHM.
• The Frequency f of a wave is how many wavelengths pass by a given point in a second. In that time, an individual oscillator in the wave goes up and down f times, as in SHM.
• Finally, there is the speed of the wave, v. The individual particles in the wave have many different velocities; some are moving up, some down, some stopped. But the overall wave has one single velocity, v, in m/s. Each second, the wave moves f wavelengths, and each wavelength is long, so the speed of the wave is

Question 2

lambda

Answer 2

• distance from top of one crest to the top of the other

Question 3

amplitude

Answer 3

• the distance from the rest position to the crest position which is half the vertical distance from a trough to a crest

Question 4

period T

Answer 4

• time for wave to move one lambda

Question 5

frequency f

Answer 5

• crests that pass per second