Guided Notes Waves: Period, Frequency, and Velocity
June 15th 2015
Catalyst/Prompt •
What is a mechanical wave? o
•
What are the three types & what are their physical properties? o o o The time required for one cycle, a complete motion that returns to its starting point, is called the ______________________ Any periodic motion has _____________________, which is the number of complete cycles in a given time Frequency is measured in ______________(Hz) Frequency depends on energy o The _____________ energy, the _________________ the frequency o The _____________ energy, the _________________ the frequency
• • • •
•
Amplitude & energy are directly proportional o The more energy, the ____________________ the amplitude Frequency & wavelength are _________________________ proportional o When frequency increases, wavelength _____________________ o When frequency decreases, wavelength _____________________
• •
Wave frequency x wavelength = wave ________________ Formula: wave speed = ______________________ x ____________________
•
Practice Problems 1. One end of a rope is vibrated to produce a wave with a wavelength of 0.25 meters. The frequency of the wave is 3.0 hertz. What is the speed of the wave? a. Formula? Wave speed = wavelength x frequency b. Plug in the #s: Wave speed = _________ x ________ = ____________
2. A wave on a rope has a wavelength of 2.0m and a frequency of 2.0Hz. What is the speed of the wave? a. Formula? Wave speed = wavelength x frequency b. Plug in the #s: Wave speed = _________ x ________ = ____________
3. A motorboat is tied to a dock with its motor running. The spinning propeller makes a surface wave in the water with a frequency of 4 Hz and a wavelength of 0.1m. What is the speed of the wave? Answer: _________ m/s 4. What is the wavelength of an earthquake wave if it has a speed of 5 km/s and a frequency of 10 Hz? Answer: ________ km 5. A tuning fork has a frequency of 280 Hz and the wavelength of the sound produced is 1.5m. Calculate its velocity. Answer: _________ m/s 6. A wave is moving towards shore with a velocity of 5m/s. If its frequency is 2.5Hz, what is its wavelength? Answer: _________ m 7. A jump rope is shaken producing a wave with a wavelength of 0.5m a frequency of 4Hz. What is its speed? Answer: __________ m/s 8. A p-‐wave travels at 30m/s along the Earth’s crust. If it has a frequency of 10Hz, what is its wavelength? Answer: _________ m 9. A compressional wave travels down a slinky going 12m/s. If it has a wavelength of 2m, what is its frequency? Answer: ___________ Hz 10. A surfer rides a wave with a frequency of 5 Hz going 25 m/s. What is the wave’s wavelength? Answer: _________ m