Superposition of Waves

Description

The above simulations show disturbances on two identical strings (position is in centimeters and time is in seconds). Simulation 1 shows two Gaussian-shaped waves of identical amplitude and width, Simulation two shows two Gaussian-shaped waves of equal and opposite amplitude and equal width, and the third simulation is shown above.

Question

At t=2.0 seconds, describe the superposition of each of the three pairs of waves.

Instructor Resources

Reference: See Giancoli-PA: 11-11, Giancoli-SE: 15-7.

Answer: Simulation 1: the waves add with double the amplitude. Simulation 2: the waves destructively interfere and at that instant, the string has zero amplitude. Simulation 3: Their sum has a large peak, a depression, and then another large peak as shown in the animation below.

Script Author: Wolfgang Christian.  Modifications by Mario Belloni and Laura Cupples.