Lecture 1: Wave Phenomena, Part 1 A surfer braves the monster waves that form in an area on the north shore of Maui called “Jaws”, where about 12 times a year, the conditions are just right to produce some of the largest waves in the world: the shape of the beach sculpts the swells that originate from as far as Alaska into 40- to 70-foot [12- to 21- meter] walls of water. Steven Kornreich

2 “Jaws”, Maui.

3 Review of Simple Harmonic Motion  Equlibrium Position The position at which all forces acting on an object sum to zero.  Displacement Change in the position of an object with respect to the equilibrium position.  Restoring Force Force that acts on the object that tends to make it move towards the Eq. position.  Simple Harmonic Motion When Restoring force proportional to the Displacement

4 Review of Simple Harmonic Motion Cont.  If we pull the mass and let go, it will begin oscillating.  It will reach a maximum displacement in each oscilation (Amplitude A)  It will reach the same point with the same velocity after a given amount of time (Period T)

5 Displacement as a function of time  y(t) = A sin (2 t/T + ) y=Displacement A=Amplitude T=Period =phase t y

6 Transverse Waves  Particle moves up- down.  Disturbance moves to the right  Particle motion and wave motion are at right angles.

7 Longitudinal Waves  Particle moves right-left  Disturbance moves to the right.  Particle motion is along the same direction as wave propagation.

8 Visualizing the wave function. Displacement of a slinky. time space displacement

9 Using 2 1-D plots.