The purpose of using epicycles and deferents to explain the motion of the planets in the night sky was to account for
a. prograde motion.
b. Mercury's and Venus's limited angular distance from the Sun.
c. retrograde motion.
d. non-uniform speed of the planets in their orbits.
e. precession of the equinoxes.
Answer: c. retrograde motion.
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The speed of sound in air is dependent upon the air temperature and other factors. The speed of sound increases from 334 m/s to 341 m/s between 8:00am and 11:00am. If a horn produces sound with wavelength 0.75 m at 8:00am, what would it produce at 11:00am?
A. 73 cm B. 77 cm C. Not enough info given to solve. D. 75 cm
Two harmonic waves are described by 
What is the magnitude of the speed (in m/s) of the two traveling waves?
A. 16 B. 4.0 C. 8.0 D. 0.25 E. 2.0
You have a choice between two lenses of focal lengths fa and fb = 2 fa to use as objective lens in building a refracting telescope. If the magnification you obtain using lens A is Ma, what will be the magnification when using lens B?
A) Mb = 2 Ma B) Mb = 4 Ma C) Mb = 8 Ma D) Mb = Ma /4 E) Mb = Ma /2
A star like the sun has a luminosity of 
How much mass must be turned into energy each second to produce this power?
A. 
B. 
C. 
D. 
E. 