# How things work college course/Waves (Physics Classroom)

This quiz was inspired by: http://www.physicsclassroom.com/class/waves/Lesson-1/Waves-and-Wavelike-Motion

• Testbank contains printable pdf files, randomized for use in a classroom.

1 These two pulses will collide and produce

 positive interference negative interference positive diffraction negative diffraction

2 These two pulses will collide and produce

 positive interference negative interference positive diffraction negative diffraction

3 These two pulses will collide and produce

 positive interference negative interference positive diffraction negative diffraction

4 Two signals (dashed) add to a solid

 octave fifth dissonance

5 Two signals (dashed) add to a solid

 octave fifth dissonance

6 Two signals (dashed) add to a solid

 octave fifth dissonance

7 Why don't we hear beats when two different notes on a piano are played at the same time?

 The beats happen so many times per second you can't hear them. The note is over by the time the first beat is heard Reverberation usually stifles the beats Echo usually stifles the beats

8 A tuning fork with a frequency of 440 Hz is played simultaneously with a tuning fork of 442 Hz. How many beats are heard in 10 seconds?

 20 30 40 50 60

9 If you start moving towards a source of sound, the pitch becomes

 higher lower unchanged

10 If a source of sound is moving towards you, the pitch becomes

 higher lower unchanged

11 Why do rough walls give a concert hall a “fuller” sound, compared to smooth walls?

 Rough walls make for a louder sound. The difference in path lengths creates more reverberation. The difference in path lengths creates more echo.

12 People don't usually perceive an echo when

 it arrives less than a tenth of a second after the original sound it arrives at exactly the same pitch it arrives at a higher pitch it arrives at a lower pitch it takes more than a tenth of a second after the original sound to arrive

13 A dense rope is connected to a rope with less density (i.e. fewer kilograms per meter). If the rope is stretched and a wave is sent along high density rope,

 the low density rope supports a wave with a higher frequency the low density rope supports a wave with a lower frequency the low density rope supports a wave with a higher speed the low density rope supports a wave with a lower speed

14 What happens to the wavelength on a wave on a stretched string if the wave passes from lightweight (low density) region of the rope to a heavy (high density) rope?

 the wavelength gets longer the wavelength stays the same the wavelength gets shorter

15 When a wave is reflected off a stationary barrier, the reflected wave

 has lower amplitude than the incident wave has higher frequency than the incident wave both of these are true

16 Comparing a typical church to a professional baseball stadium, the church is likely to have

 reverberation instead of echo echo instead of reverberation both reverberation and echo neither reverberation nor echo