Period 7 Quiz solutions

Problem 1

a) 20 cycles divided by 40 seconds = 0.5 1/s (also correct are "0.5 cycles/s" and "0.5 Hz")

b) Period = 1 / frequency = 2 seconds

c) velocity = wavelength x frequency = 8 meters x 0.5 Hz= 4 m/s

Problem 2

velocity = wavelength x frequency

first solve for wavelength = velocity over frequency = 350 m/s over 200 1/s = 1.715 meters

Problem 3 (several correct answers - make sure to explain each)

refraction, reflection, amplitude, orientation, diffraction...

Problem 4

a) read height of amplitude form graph = 0.8 meters

b) 4 meters in 6 waves, thus 4 over 6 = 0.67 meters for each wave: wavelength = 0.67 meters (you could also read off graph)

c) use velocity equation, solve for frequency: velocity = wavelength x frequency

frequency = velocity over wavelength = 10 m/s (gioven) over (2/3 meters) = 15 Hz

Problem 5

Decrease length decreases the period

Change in amplitude (as long as it is less than 30 degrees) does nothing to period & frequency