Wave problems - try all
Some review questions (and a couple new ideas).
1. Differentiate between mechanical and electromagnetic waves. Give examples.
2. Differentiate between longitudinal and transverse waves. Give examples.
3. Draw a wave and identify (or just define) the following parts: crest, trough, amplitude, frequency, period.
4. What is the frequency of a wave that travels at 25 m/s, if 3 complete waves can fit in a 10-m space?
5. Draw the first 3 harmonics for a string that is 3-m in length. Also, find the first 3 frequencies and wavelengths, if the wave speed is 100 m/s.
6. The speed of sound (in air) is approximately 345 m/s. If you stand far from a mountainside and yell at it, the echo returns to your ear in 1.8 seconds. How far is the mountain from you?
7. Approximately how much greater is the speed of light than the speed of sound in air?
8. Discuss the physics of the Chladni plate.
9. Find the wavelength of a 89.7 MHz radio wave.
1. mechanical waves (sound, strings) require a medium; EM (radio, micro, IR, visible, UV, X, gamma) do not
ReplyDelete2. longitudinal waves - the wave moves parallel to direction of travel, like a sound wave. In transverse waves, the wave movies perpendicular (up and down) to direction of travel, like a string wave
4. v = f l
25 = f (10/3)
f = 7.5 Hz
5. wavelengths: 6 m, 3 m, 2 m
frequencies: 100/6, 100/3, 100/2
6. 310 m. Use v = d/t
7. about one million times greater
9. v = f l, where v is the speed of light (3 x 10^8 m/s) and f = 89.7 x 10^6 Hz
the wavelength (l - though it should actually be lambda) is around 3 m)