Periodic Motion and Waves

Characteristics of waves 03/25/2021

Mr. Moya

Multiple Select

A pendulum oscillates as shown. At which of the following positions is the potential energy equal to the total energy?

• A

• B

• C

• Not enough information

Multiple Choice

What are the two requirements for a simple harmonic oscillator?

• The object vibrates about the equilibrium point and the restoring force is proportional to the displacement

• The object moves left to right and the restoring force is proportional to the displacement

• The object vibrates about the equilibrium and the restoring force is greater than the displacement

• The object moves left to right and the restoring force is greater than the displacement

Objective

SWBAT describe the basic characteristics of waves such as frequency, wavelength, amplitude, and period.

Frequency of a wave

• Frequency is the number of waves that pass a fixed point in unit time; also, the number of cycles or vibrations undergone during one unit of time by a body in periodic motion.

• lowercase f represent frequency.

• f = v/λ ( frequency = velocity/wavelength )

• Units = Hz or Hertz

Wavelength

• Wavelength is the distance between corresponding points of two consecutive waves.

• Lambda greek letter representswavelength (  $\lambda$  )

•  $\lambda$  = v/f  ( wavelength = velocity / frequency

Amplitude of a wave

• Amplitude is the maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position.

Period of a wave

• Period is the amount of time an object takes to make one complete wavelength.

• T represents period

• T = 1/f ( Period = 1 cycle/ frequency )

• units = s, min, hrs, ......etc.

Crest and trough

• Crest is the point on the medium that exhibits the maximum amount of positive or upward displacement from the rest position.

• Trough is the lowest point below the rest position.

• Wave height is between the crest and the trough.

Multiple Choice

These waves differ in their ___.

• amplitude

• wavelength

• wave type

Multiple Choice

What affects the amplitude of a sound wave?

• The amount of mass that is put into a wave determines its amplitude.

• The amount of gravity that is put into a wave determines its amplitude.

• The amount of energy that is put into a wave determines its amplitude.

Multiple Choice

Which of these waves has the highest frequency?

• 1

• 2

• 3

Multiple Choice

If more energy is added to a wave, what characteristic changes?

• wavelength

• wave speed

• amplitude

• wave type

Multiple Choice

A wave transfers:

• matter
• water
• energy
• particles

Multiple Choice

Which of these waves has the greatest amplitude?

• wave A

• wave B

Multiple Choice

Identify the wave measurement.

• frequency

• amplitude

• interference

• wavelength

Multiple Choice

The wave crest is represented by which letter?

• A
• B
• C
• E

Multiple Choice

Identify the wave measurement.

• frequency

• amplitude

• interference

• wavelength

Multiple Choice

Which wave has the largest wavelength?

• A
• B
• C
• None (same wavelength)

Multiple Choice

The SI unit for wavelength is ________.

• m

• m/s

• hertz

• s

Multiple Choice

The SI unit for period is ________.

• m

• m/s

• hertz

• s

Multiple Choice

The SI unit for velocity is ________.

• m

• m/s

• hertz

• s

Multiple Choice

The number of times a waves passes a given point in one sec

• frequency
• amplitude
• energy
• trough

Multiple Choice

The SI unit for frequency is ________.

• m
• m/s
• hertz
• s

Multiple Choice

The amplitude of a wave is given by

• A
• B
• C
• D

Multiple Choice

The wave trough is represented by

• A
• B
• C
• D

Multiple Choice

The wave crest is represented by which letter?

• A
• B
• C
• E

Multiple Choice

Identify the wave measurement.

• frequency

• amplitude

• interference

• wavelength

Multiple Choice

Identify the wave part

• crest

• trough

• compression

• refraction

Multiple Choice

Identify the wave part

• crest

• trough

• compression

• refraction

Open Ended

Exit ticket:

1. What letter represents the

trough

crest

wavelength

period

amplitude

height

2. What is a wavelength in your own words?

3. What is a period in your own?