12/11/08

Post date: Dec 11, 2008 1:42:53 AM

Bell Activity: Reassemble your lab station and continue your observations. Have Mr. B check your observations when you finish.

    • Finish wave table lab

    • Wave behaviors

      • Superposition of waves (click the image below to see the animation)

        • When multiple waves occupy the same space, the result is the sum of the individual waves

        • The result of the superposition of two or more waves is called interference

          • Constructive interference - wave displacements are in the same direction, leading to a larger wave than either of the component waves

          • Destructive interference - wave displacements are in opposite directions, leading to a smaller wave than the bigger of the two component waves

          • Total destructive interference - wave displacements are in opposite directions with equal magnitudes, leading to a resultant displacement of zero ... the two waves cancel each other out completely at that moment!

            • Used in noise-canceling headphones to cancel out the sounds coming from outside the headphones

      • Standing waves

        • Interference that creates points which never move, so that a wave seems not to travel down the medium

        • Node - point along the medium that does not move from equilibrium

        • Antinode - point along the medium that moves the most

      • Reflection of Waves

        • Waves reflect off a barrier at the same angle as they enter

        • Angle of incidence - Angle they hit barrier at with respect to the normal

        • Angle of reflection - Angle they leave barrier at with respect to the normal

        • Law of reflection: Angle of incidence has same measure as Angle of reflection

          • Same law applies to shots in pool when you hit the wall: the ball hits at the same angle as it leaves the wall