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20.3 Wave Interference and Energy. Date, Section, Pages, etc. Mr. Richter. Agenda. Warm Up Collect Labs Review HW Introduction to Interference Notes: The Superposition Principle Waves and Energy. Objectives: We Will Be Able To….
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20.3 Wave Interference and Energy Date, Section, Pages, etc. Mr. Richter
Agenda • Warm Up • Collect Labs • Review HW • Introduction to Interference • Notes: • The Superposition Principle • Waves and Energy
Objectives: We Will Be Able To… • Describe the superposition principle with constructive and destructive interference. • Explain which properties affect wave energy and why.
Warm-Up: • Can two waves be in the same place at the same time? • If yes, what do you think happens there? • If not, why not?
The Superposition Principle • Waves are not physical things. They are energy. • This means the more than one wave can exist in the same place at the same time. • Think about sound: can you hear more than one thing at once? • Of course!
The Superposition Principle • When waves collide, their vibrations combine. • The superposition principle states that the total vibration at any point is the sum of the vibrations of each individual wave.
The Superposition Principle: Constructive Interference • Constructive interference occurs when two wave pulses combine to make a larger amplitude. • Example: if the number of guitars playing the same note is doubled, the amplitude is increased (it gets louder!)
The Superposition Principle: Destructive Interference • Destructive interference occurs when two wave pulses combine to make a smaller amplitude. • Example: noise-cancelling head phones.
Waves and Energy • Reminder: the main idea about waves – • Waves transfer energy from place to place without transferring matter. • There are two factors that affect the energy of a wave: • frequency – how often the energy arrives • amplitude – how much energy arrives each time
Waves and Energy: Frequency • The greater the frequency of a wave, the more energy it carries. • Wave energy is proportional to frequency. • Example: trying to whip a rope more often.
Waves and Energy: Amplitude • The greater the amplitude of a wave, the more energy it carries. • Wave energy is proportional to amplitude. • Example: turning up the volume.
Wrap-Up: Did we meet our objectives? • Describe the superposition principle with constructive and destructive interference. • Explain which properties affect wave energy and why.
Homework • p. 447 #1, 2, 4, 5