NAME
ASTRONOMY 162 Online TEST 1: February 22, 2018
E = mc^2 F = ma F= Gm1m2/r^2 c = 300,000 km/sec
v = lambda*f D^3=(M1 + M2 )P^2 lambda= 3000/T E/area =sig*T^4
part 1: 4 points for each multiple choice question
1. The reaction p + p -> Deuterium + positron + neutrino
a) involves the weak nuclear force
b) involves the strong nuclear force
c) occurs at temperatures more than 5,000,000 degrees K
d) all of the above
2. The star Deneb is directly overhead of DeKalb at 8 PM on October 5. On July 5, it is directly overhead at:
a) 8 PM
b) 10 PM
c) 12 midnight
d) 2 AM2.
3. Fusion reactions release energy due to
a) E = mc^2
b) electromagnetic interactions
c) the Sun's convective layer
d) breaking of chemical bonds
4. The Doppler effect causes light emitted from a body moving toward the observer to be
a) unchanged
b) shifted to lower frequencies (red shift)
c) shifted to higher frequencies (blue shift)
d) shifted to lower wavelengths (yellow shift)
5. In addition to the Earth, how many planets can be seen with the unaided eye??
a) 4
b) 5
c) 6
d) 7
6. DeKalb is at 42 degrees North latitude. To an observer there, Polaris, the North Star
a) issometimesseen to be directly overhead
b) isalways seen to be 48 degrees above the north horizon
c) is seen to change its location with the seasons
d) none of the above
7. Which of the following describes geometric parallax?
a) the process where light is bent going through a lens
b) a geometric method used to measure the distance to remote objects
c) the apparent east-to-west motion of planets relative to the stars
d) the process where hydrogen is converted to helium
8. Given an asteroid's orbit is close to being circular and its distance from the Sun is
3 AU, its orbital period about the Sun is
a) Indeterminate without additional information
b) about 3 years
c) about 5 years
d) about 7 years
9. The Sun’s total lifetime will be about
a) 10 million years
b) 1 billion years
c) 10 billion years
d) 1 trillion years
10. Electromagnetic emissions in the infrared part of the spectrum have
a) larger wavelengths than does visible light
b) smaller wavelengths than X-rays
c) smaller velocities than sound waves
d) smaller wavelengths than visible light
Section 2. Write a short paragraph on something you have found interesting in this course. 10 points
Section 3: Short Answers 12 points each. Do both of questions A and B.
A. Name three astronomical observations made by Galileo. Why wereeach important in the context of the time (1610)?
B. What are Kepler's three laws of planetary motion? Use Newton's laws of motion and gravity to briefly explain one of Kepler's laws. (do not just write down Newton's laws)
Section 4. Short Answer 13 points. Do two of questions D, E, or F. If you do all threeonly the first twowill be graded.
D. What are the four forces in Nature? Give an example for each one from our class.
E. In general, what causes light and other electromagnetic radiationto be emitted? Also, specifically state what causes the continuousand discrete spectrums discussed in the lectures givingan example of each.
F. Show the three nuclear reactions which convert 6 protonsinto Helium 4 (2 protons plus 2 neutrons) plus 2 protons plus other particles.Why do these processes cause energy in the form of heatto be produced?