Chapter 25

Chapter 25

1. Vibration of Pendulum

   • Period-time of back and forth swing of pendulum
   • Period of pendulum only depends on the length of the pendulum

2. Wave description

   • Simple harmonic motion- back and forth vibration motion
   • trough-low point of wave
   • Crest- hight point of wave
   • SIne curve- pictorial representation of wave
   • amplitude- distance from midpoint to crest (or trough) of wave.
   • wave- a disturbance that is transmitted with no transport of matter
   • Wave length- distance from one point on the wave to the other

3. Frequency- number of vibrations an object makes in a unit of time. Measure in Herts (Hz)

4. Frequency and Period are inverses of each other

   • 1/period = frequency
   • 1/frequency= period

5. The energy transferred by a wave from a vibrating source to a receiver is carried by a disturbance in a medium

6. Calculate the speed of the wave by multiplying the wavelength by the frequency

7. Transverse waves- whenever the motion of the medium is at right angles to the direction in which a wave travels

8. When the particle in the medium oscillate parallel to or along the direction of the wave rather than at right angles to it, the wave is a longitudinal wave

9. Doppler effect- as a wave source approaches, an observer encounters waves at a higher frequency. As the wave source moves away, and observer encounters waves with a lower frequency

   • increase in frequency of light = blue shift
   • decrease in frequency of light = red shift