Homework 4.

Good ones to think about:

1. Review # 4, p. 144. The Earth's weather erodes our craters.

2. Review # 1, p. 226. The inner planets are rocky. They were formed at high temperatures, so H, He, and other "volatiles" were "cooked" off of them by the Sun's energy.

The Jovian planets are more gassy. They were formed at cold temperatures, far from the Sun, so gases & volatiles could condense onto the planetesimals, and wern't "baked out."

3. Review # 4, p. 324: a neutrino ain't a neutron!

masses differ, neutrons react by strong force, neutrinos hardly react at all

4. Thought # 10, p. 324.

big ones from little ones, a.k.a., FUSION: a., b., d., e.

little ones from big ones, a.k.a., FISSION: c.

5. Review #15, p., 325.

convection: convection oven, boiling liquids

radiation: microwaves, camp fire, sunhine on my shoulder




Hand these in:

1. Review #3, p.144. Full credit for four each. (4 pt.)
terrestrial planets
closer to Sun
most heat from Sun
rocky
warm
smaller
no rings
few moons
Jovian planets
farther from Sun
most get most heat from internal heat sources
compsed primarily of gas and "volatiles"
cold
large
rings
many moons

2. Review #6, p.182. (4 pt.)

  1. sister theory = formed with Earth: but Moon's too unlike Earth
  2. capture theory = formed elsewhere, Earth's gravity captured it: but Moon's too much like Earth
  3. fission theory = Moon split from Earth: but Moon's too different from Earth
  4. giant impact = large foreign body hits Earth, and it and terrestrial debris congeal into Moon: best theory

3. Thought #8, p.205, first question only. (1 pt.) Venus is cloudy, so we can't see the surface in the visible range. Hence, it makes sense to use a different wavelength for imaging.

4. Review #8, p. 246. (3 pt.) -- credit given for first two, and plausible attempt at third

  1. breakup of moon(s) due to tidal forces of planets' gravity
  2. moons never formed in the first place -- planet's gravity too strong
  3. breakup of moon(s) due to collisions with foreign bodies (mentined slighlty after first two)

5. Review #5, p. 266. (2 pt.) The text outlines three chioces: orbit Sun until breakup, impact with a planet, or ejection from solar system

6. Problem #20, p. 284. (5 pt.)

7. Review #3, p. 306. (2 pt.) They're colder than the surrounding atmosphere.

8. Review #5, p. 306. (3 pt.) -- many choices! here're three, all conveniently listed in the chapter summary:

  1. sunspots
  2. solar flares
  3. prominences

9. Review #2, p. 324. (4 pt.)

If the Sun was fueled by either method, it would've burned out too quickly.

10. Review #5, p.324. (2 pt.)

Any reasonable approximation of the following will get full credit: Hydrostatic equilibrium means that the Sun's outward gas pressure is balanced by the inward force of gravity, so the Sun is neither contracting or expanding, but is constant in size. ("hydro-" = fluid, like the Sun's gassy interior; "static" = constant; "equilibrium" = balance)