PHYS 6B Final: Physics 6B practice final solutions short
14
PHYS 6B Full Course Notes
Verified Note
14 documents
Document Summary
Practice final solutions: two speakers placed 4m apart produce sound waves with frequency 425hz. A listener is standing 3m in front of the left speaker. Assume the speed of sound is 340 m/s. First find the distance from the right speaker (use the pythagorean theorem or recognize the 3-4-5 right triangle). Now find the difference in the distances to each speaker: (5m 3m) = 2m. We need to compare this to the wavelength of the sound. This means the difference is 2. 5 wavelengths, yielding destructive interference (a quieter sound: charge q1 = -5. 4 c is placed at the origin, and charge q2 = -2. 2 c is on the x-axis at x=1m. Here is a diagram, with q3 in between. We just need to find the forces on q3 due to the other charges, and make them equal. We are not given the sign of charge q3, but it shouldn"t matter.
