1. Wave Motion Types waves –mechanical waves require a medium to propagate –sound wave, water wave –electromagnetic waves not require a medium to propagate –visible light, radio waves, television signals, and x- rays

2. Wave Motion Types waves –transverse wave A traveling wave or pulse that causes the elements of the disturbed medium to move perpendicular to the direction of propagation –longitudinal wave A traveling wave or pulse that causes the elements of the medium to move parallel to the direction of propagation

3. Transverse wave

4. Longitudinal wave

5. Wave Motion

6. wave function

7. Wave Motion if the pulse travels to the left wave function

8. Example A Pulse Moving to the Right

9. Sinusoidal Waves Wavelength, (m) –minimum distance between any two identical points Period, T (s) –time interval required for two identical points Frequency, f (Hz) –number of crests (or troughs, or any other point on the wave) that pass a given point in a unit time interval Amplitude, A (m) –maximum displacement from equilibrium of an element of the medium

10. Sinusoidal Waves

11. Wave number Angular frequency Wave speed phase constant,

12. Example A sinusoidal wave traveling in the positive x direction has an amplitude of 15.0 cm, a wavelength of 40.0 cm, and a frequency of 8.00 Hz. The vertical position of an element of the medium at t = 0 and x = 0 is also 15.0 cm, as shown in Figure –Find the wave number k, period T, angular frequency and speed v of the wave. –Determine the phase constant and write a general expression for the wave function.

13. Sinusoidal Waves on Strings Because the end of the blade oscillates in simple harmonic motion, each element of the string, such as that at P, also oscillates vertically with simple harmonic motion.