NAME:___________________________________

 SECOND EXAM

MARK YOUR ANSWERS ON THIS SHEET AND TURN IT IN.

c=3x10¹⁰         G=6.7x10^-8      h=6.6x10-27     s=5.7x10^-5

1pc=3x10¹⁸cm             1AU=1.5x10¹³cm        M_sun=2x10³³g               R_sun=7x10¹⁰cm

                            F=ma                    x=vt                 v=at

 MULTIPLE CHOICE 

 _____ 1. The spectrum of continuous (blackbody) radiation can be used to find the temperature of a distant object by
a) identifying the elements from bright lines
b) determining the wavelength of maximum emission
c) filtering out the red light
d) noticing that some wavelengths are entirely missing
e) noting that the amount of energy decreases with distance

_______ 2. At the end of its life, the sun will expand to many, many times its current radius.  Assuming the temperature stays the same, what is the increase in luminosity (energy output) if the sun increases in radius by a factor of 10?
 a) no increase b) 10 times  c) 100 times d) 1000 times  e) 10,000 times

 _____ 3. Asteroid X orbits the Sun in eight years.  How many AU is it from the Sun?
a) 0.125  b) 1  c) 4  d) 8  e) 64

 ______ 4. Our TA is ticketed for running a red light.  His defense to the traffic judge is that he was traveling so fast, the red light had doppler shifted to be a green light.  How fast must Randy have been going for this to have happened?
a) 30 miles/hr b) 55 miles/hr  c) 100 miles/sec  d) 50,000 miles/sec e) one million miles/sec

_____ 5. The thermal radiation from solid objects (such as rocks) contains strong emission lines.  True or false?
a) true  b) false

 _____ 6. Emission and absorption lines in astronomical objects are used to:
a) measure the distance to the object
b) measure the velocity of the object
c) measure the size of the object
d) measure the angle of the object
e) none of these

 _____ 7. An apple dropping to Earth accelerates at 1000cm/s/s for 3 seconds.  How fast is it going at the end of the 3 seconds?
a) 3cm/s  b) 30cm/s  c) 300cm/s  d) 3000cm/s   e) 30000cm/s

 _____ 8. The star Capella is yellow, Proxima Centauri is red, Procyon is green, Arcturus is orange, and  Rigel is blue.  Which is coolest?
a)Capella b)Proxima Cen c)Procyon d)Arcturus e)Rigel

_____ 9. The relation between a photon's wavelength and its frequency is given by:
a)wavelength times the speed of light equals frequency
b)frequency times the speed of light equals wavelength
c)wavelength times frequency equals the speed of light
d)wavelength times frequency equals energy
e)wavelength divided by frequency equals the speed of light

 ______ 10. If the Moon were to have oceans, how long would it be between high tides?
a) 6 hours b) twelve hours c) two weeks d) no tides

 _______ 11. Name the four forces of nature in order of increasing strength, weakest first.

_______ 12. Name the six principal bands of the electromagnetic spectrum in order of increasing wavelength, shortest first.

Answers: 1b,2c,3c,4d,5b,6b,7d,8b,9c,10c,13a,14c,15e,16e