Standard S8P4

Students will explore the wave nature of sound and electromagnetic radiation.

You will observe the movement of a wave and determine the source of the wave’s energy. Copy & answer questions.

1. In which direction does the wave move?

2. How does the movement of the rope compare with the movement of the wave?

3. Where does the energy of the wave come from?

Elements S8P4.a and S8P4.f

a) Identify the characteristics of electromagnetic and mechanical waves.

f) Diagram the parts of the wave and explain how the parts are affected by changes in amplitude and pitch.

Definition of a Wave:1)Disturbance transmitting energy through matter or empty space.

2) Does work on everything in its path

Wave Classification

Group #1 MECHANICAL WAVES

Waves that require a medium

Group #2 ELECTROMAGNETIC WAVES

Waves that do not require a medium

A medium may be a gas, a solid, or a liquid. Simply put a medium is the material through which a wave transfers energy.

A. Wave that require a medium

Examples

1. Ocean waves

2. Earthquakes

• Cause rhythmic disturbance in the medium

• Travel through medium

• Transmit energy

• Leave the medium unchanged after the wave passes

Do not require a medium

Transfer energy.

Examples

1. Radio waves

2. Visible light

1. Different Movements of Waves

2. Physical Characteristics a Transverse Wave

3. Calculation of Wave Velocity

Transverse waves – Medium moves at right angles to the direction of the wave

Longitudinal Waves – Medium moves in the same direction as the waves are moving

Transverse waves – Medium moves at right angles to the direction of the wave

Longitudinal Waves – Medium moves in the same direction as the waves are moving

Waves Website

A. Crest

The highest point of a wave

B. TroughThe lowest point of a wave

Wavelength c) The distance between

a point on one wave and the identical point on the next wave.

Wavelength d) Represented by the

Greek letter lambda λ

Amplitude

The distance from the crest or trough of a wave to the rest position.

Frequency

a. The number of waves crests of a wave that pass one place in one second

Frequency

b. Frequency is measure in hertz (Hz).

One hertz = one wave per second

Frequency

c. Frequency is represented by the letter f.

Frequencyd. Example A: If ten wave crest pass a

point every five seconds, what is the frequency of the wave?

Frequencyd. Example A: If ten wave crests pass

a point every five seconds, what is the frequency of the wave?

f = ten waves / 5 seconds

f = 2 hertz

Formula:

Velocity = wavelength x frequency

v = λ x f

Example: A wave is generated in a wave pool at a water amusement park. The wavelength is 4.0 m. The frequency of the wave is 0.50 Hz. What is the velocity of the wave?

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1. A wave moving along a rope has a wavelength of 1.2 m and a frequency of 4.5 Hz. How fast is the wave traveling along the rope?

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2. An ocean wave has a length of 10.0 m. Two waves pass a fixed point every 1.0 seconds. What is the speed of the wave? (Hint: Determine the frequency of the wave first.)

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Now you Try….• 1. Determine the wave speed of a wave that has

a wavelength of 5 m and a frequency of 4 Hz.

• 2. What is the frequency of a wave if the wave has a speed of 12 cm/s and wavelength of 3 cm.?

• 3. A wave has a frequency of 5 Hz and a wave speed of 18 m/s. What is its wavelength?

Okay seat partners….

Write your answers to the next question on a magnetic board. You will have 10 seconds.Do not reveal your answers until asked to do so.

1.What do waves carry?

2. The distance between two wave crests is known as……

3. A wave passes you every 0.5 seconds. What term is used to describe the number of waves passing a given point?

4. Which type of wave has compressions and rarefactions?

5. Draw a transverse wave.

6. What do you call the material that a wave travels through to transfer energy?

Waves Comprehension Check

• 1. Name of Wave

• 8. Definition of Wave

• 9. Name of Wave

• 13. Another Name for the Wave

• 14. Definition of Wave

• # 4 is a BONUS