Waves & Optics- Standing Waves

Question 1

Standing Waves

Answer 1

• , Unlike travelling waves, standing waves do not appear to travel
• Each point on the standing wave oscillate about a point on the axis of the wave.
• Adjacent points are in phase with each other so that points of a particular phase remain at a fixed location as time progresses
• Adjacent points each oscillate with a different amplitude
• Since adjacent in phase, no energy is transferred from one point to the next, unlike a travelling wave.
• Standing waves are formed by the superposition of two travelling waves of the same frequency travelling in opposite directions
• usually achieved by a travelling wave and its reflection
• Antinodes are points on a stationary wave that oscillates with maximum amplitude
• Nodes are points of zero amplitude and appear to be fixed.

Question 2

Standing Waves in Strings and Pipes

Answer 2

• If a string has fixed ends, these cannot oscillate
• any stationary waves on it must have nodes at both.
• The first harmonic is the lowest frequency of the standing wave that can be supported on the system
• The second, third, fourth and so on harmonics are simple multiples of this fundamental frequency