PHYSICS 109 Lecture Notes - Lecture 4: Standing Wave, Fundamental Frequency
Document Summary
Physics 109 - lecture 4 - strings (9/19/2016) Wave on a string with a fixed end. If a wave propagates down a string and reaches the fixed end, the wave is reflected and travels in the opposite direction. Superposition of two waves with same frequency that are moving in opposite directions. To find the period, find 2l - the length of the string multiplied by two. Finding 2l is important because to measure the period of the wave, you have to measure the round trip. Also find v - speed of propagation. Formula t = 2l/v or since f = 1/t, f = v/ 2l. Similarly, amplitudes add coherently when f = nv/2l, n = any integer. Sum (superposition) of two waves with same frequency moving in opposite directions. Node - point on the string where the string never moves/ amplitude = 0. Antinode - point on string where amplitude is at maximum or minimum.
