Kepler's first law of planetary motion implies that
a. the planets move at a constant speeds at all points in their orbits.
b. the planets all move around the Earth in elliptical orbits.
c. uniform circular motion is adequate to describe the motion of all planets.
d. planets move in elliptical orbits around the sun.
Question 2Stars are born in
a. reflection nebulae.
b. dense molecular clouds.
c. HII regions.
d. the intercloud medium.
e. the local bubble.
Question 3Kepler's second law implies that
a. a planet should move at its greatest speed when it is closest to the sun.
b. the most massive planets will have the greatest speed in their orbits.
c. the speed of a planet in its orbit depends on the size of the epicycle.
d. the mass of the planet determines how far the planet is from the sun.
e. the deferent and the epicycle have to be attached to the sun and not Earth.
Question 4Absorption lines due to the interstellar medium indicate that some components of the interstellar medium are cold and of a very low density because
a. the lines are blue shifted.
b. the lines are red shifted.
c. the lines are extremely broad.
d. the lines are extremely narrow.
e. the lines are much darker than the stellar lines.
Question 5The ____ of an object is a measure of the amount of matter it contains. On the other hand, ____ is a measure of the gravitational force on an object.
a. weight, mass
b. mass, weight
c. energy, force
d. force, energy
e. momentum, energy
Question 6____ are small dark nebulae about 1 light-year in diameter that contain 10 to 1,000 solar masses.
a. HI regions
b. HII regions
c. Emission nebulae
d. Bok globules
e. Reflection nebulae
Quick Reply
