- #1

astronomystudent

- 96

- 0

1.) The frequency of WUSC is 90.5 x 10^5 cycles per second. What is the wavelength?

I used C = wavelength (frequency)

Thus: 3x10^8 m/s = wavelength (90.5 x 10^5)

wavelength = 3.314917127 m

wavelength = 3.31 x 10^9 meters

2.) If the period for a certain satellite revolving in a polar orbit around the Earth is 2 hours, how high above the surface of the Earth does it orbit? What if this same satellite were orbiting Jupiter (mass 318 times the mass of Earth) with the same 2 hour period. How high above the center of Jupiter would it be orbiting?

I know you use Kepler's 3rd law for this and I can fill in most of the numbers for the equation by I am confused as to what is meant by "above the surface" and "above the center of Jupiter" does that have to do with semi-major axis maybe?

3.) 1.75 x 10^5 arcsec is how many degrees? (remember significant digits !)

I found this conversion: 1 arc second = 0.000277777778 degrees

I then set up a table to solve the problem:

0.000277777778 degrees/1 arc second = 1.75 x 10^5 arc seconds/x (degrees)

everything cancels out you multiply and then divide 1.75x10^5/0.000277777778

x = 6.29 x 10^8 degrees

4.) Suppose the sound from an approaching train whistle normally has a frequency of 1200 cycles per sound, but the train is approaching at 50 meters per second. How would the Doppler effect change the wavelength of the sound? (speed of sound 335 meters per second; quantitative answer here for full credit)

I know here that as the train whistle approaches the sound waves will have shorter wavelengths and higher frequencies, as it passes however, that will change and the frequencies will be lower. I am working on the math part.

I used C = wavelength (frequency)

Thus: 3x10^8 m/s = wavelength (90.5 x 10^5)

wavelength = 3.314917127 m

wavelength = 3.31 x 10^9 meters

2.) If the period for a certain satellite revolving in a polar orbit around the Earth is 2 hours, how high above the surface of the Earth does it orbit? What if this same satellite were orbiting Jupiter (mass 318 times the mass of Earth) with the same 2 hour period. How high above the center of Jupiter would it be orbiting?

I know you use Kepler's 3rd law for this and I can fill in most of the numbers for the equation by I am confused as to what is meant by "above the surface" and "above the center of Jupiter" does that have to do with semi-major axis maybe?

3.) 1.75 x 10^5 arcsec is how many degrees? (remember significant digits !)

I found this conversion: 1 arc second = 0.000277777778 degrees

I then set up a table to solve the problem:

0.000277777778 degrees/1 arc second = 1.75 x 10^5 arc seconds/x (degrees)

everything cancels out you multiply and then divide 1.75x10^5/0.000277777778

x = 6.29 x 10^8 degrees

4.) Suppose the sound from an approaching train whistle normally has a frequency of 1200 cycles per sound, but the train is approaching at 50 meters per second. How would the Doppler effect change the wavelength of the sound? (speed of sound 335 meters per second; quantitative answer here for full credit)

I know here that as the train whistle approaches the sound waves will have shorter wavelengths and higher frequencies, as it passes however, that will change and the frequencies will be lower. I am working on the math part.

Last edited: