topic : waves aim : describe the electromagnetic spectrum. do now : next slide

Topic: Waves

Aim: Describe the electromagnetic spectrum.

Do Now: Take out your electromagnetic waves reading notes.

Take out your waves reading notes – Complete #’s 1 - 7

HW: Magnetism Reading notes and Gravity ISN due Friday 5/29

Get your chemistry test signed.

CL Waves due Thursday 5/28

1. Identify then type of wave represented. 2. Identify a crest by placing a large dot where it is located and

writing “CREST” near the dot.

3. Identify a trough by placing a large dot where it is located and writing “TROUGH” near the dot.

4. Identify and label a wavelength by drawing a line to represent your wavelength. Write “WAVELENGTH” on top or below the line.

5. How many wavelengths are visible in this diagram?

Transverse

Crest

Trough

Wavelength

2

1. Identify then type of wave represented.

Longitudinal wave

2. Identify the parts of this wave labeled A and B.

A – Compression

B- Rarefaction

A B

Identify the wave behavior in the diagrams below. Support your answer.

AB

Refraction is when the wave bends.

Reflection is when the wave bounces off the surface.

Any substance through which a wave can travel is called a

1.solid 

2.vacuum   

3.medium 

4.liquid

Waves transfer

1.energy

2.matter

3.particles

4.heat

Which of the following is the best example of a wave?

1.A stone rolling downhill

2.A vehicle moving on a bumpy road

3.A string vibrating on a guitar

4.A grasshopper jumping up and down

1. What kind of waves are electromagnetic waves? Support your answer.

• Transverse waves • Bc electric field and

magnetic field are positioned at RIGHT ANGLES to each other and to the motion of the wave

2. Explain why electromagnetic waves can travel through a vacuum.

• They do not carry energy by causing matter to vibrate

Speed ofan EW

•In a vacuum = –300 million m/s –Speed of light

3. Describe what happens to the frequency as you move from left to right on the electromagnetic spectrum.

• Frequency increases.

4. Describe what happens to the energy as you move from left to right on the electromagnetic spectrum.

• Energy increases.

5. Describe what happens to the wavelength as you move from left to right on the electromagnetic spectrum.

• Wavelength decreases.

6. Identify the electromagnetic waves with the lowest frequency and energy.

• Radio waves

7. Identify the electromagnetic waves with the greatest frequency and energy.

• Gamma rays

8. Identify the electromagnetic waves with the longest wavelength.

• Radio waves

RADIO WAVES - Used for radio, TV, cell phones, MRI’s

9. Identify the electromagnetic waves with the shortest wavelength.

•Gamma rays

10. Describe what happens to the energy of a wave as its wavelength gets smaller.

• Energy increases as wavelength gets smaller.

11. Which type of wave can cause our skin to burn during the summer?

• UV waves

•Kills bacteria

•Make some materials fluorescent–Fluorescent powder show fingerprints

12. Which wave are used for radar images?

•Microwaves

13. Which types of waves are visible?

•Visible light waves

Light is a type of electromagnetic wave. In matter, it’s speed

depends on the medium it travels though.

14. Which color light has the longest wavelength?

•RED

15. Which type of wave can be felt as heat?

• Infrared waves

Ex: Remote controls emit infrared waves to control TV

•Computers - to read CD-ROMs.

•Thermal imaging

16. Why do we use X-Rays?

•Doctors can look at our bones

•Airport screening devices

17. Describe one disadvantage of using gamma rays to kill cancer cells.

•They kill all living cells.

•Produced during nuclear reactions (in nucleus of atoms)

Used in radiation therapy to kill cancer cells

Let’s summarize…

1.Identify the type of waves elecromagnetic waves are.

2.How are electromagnetic waves arranged in the electromagnetic spectrum?

3.Describe each type of EW in the Electromagnetic spectrum.

http://www.youtube.com/watch?v=7hwzG0YI9ms

http://www.youtube.com/watch?v=cfXzwh3KadE

http://www.pbslearningmedia.org/resource/npe11.sci.phys.energy.emxray/tour-of-the-electromagnetic-spectrum-x-rays/http://www.youtube.com/watch?v=PPlrtgilgK8

In an electromagnetic wave, an electric field exists perpendicular to the direction of travel of the wave. These characteristics indicate that an electromagnetic wave is which of the following wave types?

a.gravitational b. longitudinal

b. mechanical d. transverse

When comparing the types of electromagnetic waves, which has the greatest energy?

a.Ultraviolet

b.X-rays

c.Gamma rays

d.Visible

Which of the following is a similarity between x-ray waves and sound waves?

a.Both transfer energy.

b.Both require a medium.

c.Both have the same speed.

d.Both have the same frequency.

The figure below shows regions of the electromagnetic spectrum.

Radio Microwaves Infrared Visible UV Gamma

Which of the following waves has the highest frequency?

a.Visible light c. microwaves

b.UV rays d. infrared radiation

What property of electromagnetic waves makes it possible to use these waves to transmit information between a space shuttle and NASA mission control centers on the ground?

a.EW’s are transverse waves.

b.EW’s have a very low velocity.

c.EW’s are all visible to the human eye.

d.EW’s can travel through a vacuum.

Which of the following statements applies to longitudinal waves?

1.The motion of the medium is random.

2.The motion of the medium is in a circular pattern.

3.The motion of the medium is parallel to the motion of the wave.

4.The motion of the medium is perpendicular to the motion of the wave.

Sound reaches our ears because sound makes particles

1.heat up.

2.slow down.

3.cool down.

4.vibrate.

The distance between the Earth and the moon was determined by measuring the time it took for light waves from the Earth to travel to the moon and back. Why was it not possible to use sound waves for this experiment?

1.Sound waves must move through a substance.

2.Sound waves change frequency on the return to earth.

3.Sound waves move too slowly for this technique to be accurate.

4.Sound waves move more slowly in the Earth’s atmosphere than in space.

A large spring is stretched horizontally between 2 people. One person wiggles the spring up and down at one end. The up-and-down vibration then moves along the spring on to the other person. Which of the following type of wave is created in the spring?

1.pressure wave

2.longitudinal wave

3.transverse wave

4.nonmechanical wave

Identify the kind of wave represented in each diagram. Support your answer.

longitudinal wave

transverse wave