TOPIC Energy AIM Describe the characteristics of waves
TOPIC: Energy AIM: Describe the characteristics of waves. Do Now: Review Question #1 on 2 nd page of KE and PE reading notes HW: CL Energy due Tuesday, Energy Exam on Wednesday
If both of these balls are traveling down a bowling lane at the SAME speed, which one would have more kinetic energy? Support your answer. Ball A. It has a greater mass.
1. Define the term wave. • Traveling disturbance that carries energy from one place to another • REPEATING disturbance
2. Describe • VIBRATIONS the cause • Any movement that of waves. follows the same path repeatedly
Slinky waves can be made by vibrating the coil back & forth in either a horizontal or a vertical direction.
3. Define a • The movement of energy wave using from a vibrating source. the terms energy and vibrating.
A pebble tossed into the water will create a circular disturbance which travels outwards in all directions. The pebble transfers some of its energy to nearby water molecules causing them to move. These water molecules transfer this energy to molecules around them. Energy is traveling in the form of a wave on the surface of the water.
A tuning fork forces air particles to vibrate creating sound.
4. Identify • MEDIUM the matter waves pass through.
5. Identify a. Ocean Waves the WATER medium for the following waves: b. Sound waves AIR
6. Describe the main difference between mechanical and electromagnetic waves. • Mechanical waves require a medium – Ex: Sound waves – Sound can’t be heard in outer space – Why? ? ? • Bc outer space is a vacuum • Electromagnetic waves does not require a medium
The sound produced by the bell cannot be heard since sound can’t travel through a vacuum. It is a mechanical wave.
• Region where no matter Vacuum exists • Example: outer space
7. Identify the 3 characteristics that all waves have. • Amplitude • Wavelength • Frequency
Normal resting position
Crest Trough
• Crest – high points • Trough – lowest points
Amplitude
• Amplitude – height –Distance from crest/trough to rest –High amp = a lot of energy
A B Which waves have a high amplitude?
Wavelength
• Wavelength – distance bw 2 crests or 2 troughs
A B Which waves have a shorter wavelength?
• Frequency: • # of complete waves per unit of time
A B Which waves have a higher frequency?
A B Which waves have a shorter wavelength?
11. How are • Transverse waves • Longitudinal classified?
Can you see the difference between these two waves? Hint…look at the movement of the particles (medium).
12. Describe • Motion of particles is at the motion RIGHT ANGLE to the of the direction of the wave. medium in a transverse wave.
Direction of particles Direction of wave (PERPENDICULAR)
13. Identify • Wave on a rope examples • Light and other of electromagnetic waves transverse • Ocean waves.
14. Describe • Particles of medium the motion move PARALLEL to the of the direction of the wave medium in a longitudinal • Compressional waves wave.
15. Describe • Series of compressions what a and rarefactions longitudinal wave consists of.
Direction of particles (left & right) Direction of wave (BACK AND FORTH)
16. Describe the difference between a rarefaction and a compression.
• Rarefaction: space in medium where there are fewer particles • Compression: space in medium where particles are crowded together rarefaction A B compression
B A C D E F
17. Identify • Sound waves an example of a longitudinal wave.
Forces in Earth’s crust can cause regions of the crust to shift, bend, or even break. The breaking crust vibrates, creating seismic waves that carry energy outward. Seismic waves are a combination of compressional and transverse waves. They can travel through Earth and along Earth’s surface. The more the crust moves during an earthquake, the more energy is released.
Let’s summarize… 1. What is a wave? 2. Identify the cause of waves. 3. Describe a medium. 4. Identify an example of a medium. 5. Describe a vacuum. 6. Explain the difference between mechanical and electromagnetic waves. 7. Explain the difference between transverse and longitudinal waves. 8. Identify an example of a mechanical wave, electromagnetic wave, transverse wave and longitudinal wave.
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
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
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