assignment 13

course phys 202

1.how do we determine the energy of a standing wave given the amplitude and frequency of the wave and the mass of the string?-Energy = 2*pi^2*m*f^2*A^2

2. If the ends of two strings are driven in phase by a single simple harmonic oscillator, and if the wave velocities in the strings are identical, but the length of one string exceeds that of the other by a known amount, then how do we determine whether a given frequency will cause the 'far ends' of the strings to oscillate in phase?

- in order to determine whether a given frequency will cause the ends to oscillate in phase is to find out how much extra the one string is, because it needs to be a whole integer

3.what are the wavelength ranges?

- F= 550 kHz = 550 * 10^3 Hz = 5.5 * 10^5 Hz will correspond to a wavelength of 3 * 10^8 m/s / (5.5 * 10^5 cycles / sec) = 545 meters.

-F= 1600 kHz = 1.6* 10^6 Hz will correspond to a wavelength of 3 * 10^8 m/s / (1.6 * 10^6 cycles / sec) =187 meters.

-F= 88.0 mHz= 88.0 * 10^6 Hz = 8.80 * 10^7 Hz will correspond to a wavelength of 3 * 10^8 m/s / (8.80 * 10^7 cycles / sec) = 3.41 meters.

4. What are the possible frequencies of a violin string whose fundamental mode vibrates at 440 Hz?

1st fundamental frequency = 440 Hz

2nd harmonic frequency = 2 * 440 Hz = 880 Hz

3rd harmonic frequency = 3 * 440 Hz = 1320 Hz

4th harmonic frequency = 4 * 440 Hz = 1760 Hz

5.Earthquake intensity is 2.0 * 10^6 J / (m^2 s) at 48 km from the source. What is the intensity at 1 km from the source?

- we want to use the formula pwr/SA, so 2300 * 2 * 10^6= 4.6 *10^9

6. At what rate did energy pass through a 5.0 m^2 area at the 1 km distance?

- 4.6 * 10^9 J / (m^2 s) * 5.0 m^2 = 2.3 * 10^10 J / s, or 23 billion wat

I think you're OK here but I can't evaluate your work here unless your responses are inserted as instructed into a complete copy of the 'open' qa or query.