Download Homework, August 29, 2002 AST110-6

Homework, October 5, 2006
AST110-6
Due Date: Tuesday, October 17, 2006
1. Chapter 6, Problem 6 (20pt). Describe each of the three key processes that led the
solar nebula to take the form of a spinning disk. What observational evidence
supports this scenario?
In our planetary nebula theory for the formation of the solar system, the timing of the
solar wind determines what kind of planets we should have in our solar system. Answer
the following two questions:
2. Chapter 6, Problem 25. A Cold Solar Nebula. (20pt) Suppose the entire solar nebula
had cooled to 50 K before the solar wind cleared it away. How would the composition
and sizes of the planets of the inner solar system be different from what we see today?
Explain your answer in a few sentences.
3. Chapter 6, Problem 26. No Gas Capture (20pt). Suppose the solar wind had cleared
away the solar nebula before the seeds of the Jovian planets could gravitationally
draw in hydrogen and helium gas. How would the planets of the outer solar system be
different? Would they still have many moons? Explain you answer in a few
sentences.
Radiometric Dating
4. Chapter 6, Problem 13 (20pt). Briefly explain the technique of radiometric dating,
and describe how we use it to determine the age of the solar system.
5. Chapter 6, Problem 29 (20pt). You are analyzing rocks that contain small amounts
of potassium-40 and argon-40. The half-life of potassium-40 is 1.25 billion years.
a. You find a rock that contains equal amounts of potassium-40 and argon-40. How
old is it? Explain.
b. You find a rock that contains three times as much argon-40 as potassium-40. How
old is it? Explain.