Physics 7 (Winter 08) – Homework #2

Due: 1/22

 

1.      Explain briefly how Copernicus explained the absence of hurricane-strong winds at the Earth’s equator, even if the Earth rotates about its axis at 1000 mi/hr at the equator.

2.      The Copernican hypotheses explained the retrograde motion of Mars by

a)      Assuming that the Earth and Mars orbit the Sun at different speeds

b)      Assuming Mars rotates about the Earth

c)      Assuming Mars does not rotate at all

d)     Claiming that the observations are incorrect

e)      Asserting that the effect is due to Jupiter’s gravitational pull

3.      Aristotle argued that the universe is eternal because

a)      He could think of no alternative

b)      It was a condition necessary for planets to move in circles around the Earth

c)      Otherwise the universe would change and it would then be fundamentally imperfect

d)     It follows from the hypothesis that natural motion is determined by nature

e)      Otherwise it could not be geocentric.

4.      The geocentric hypothesis was replaced by the heliocentric one because

a)      The Church lost power after the Middle Ages

b)      The heliocentric hypothesis provided a more accurate description of the data

c)      Copernicus’ philosophy was more intellectually satisfying than Aristotle’s.

d)     Astronomers felt that it was time for a change

e)      None of the above.

5.      According to Kepler’s ideas if we were to observe an alien stellar system with two planets,

a)      These planets would necessarily move in perfect circles around the Earth

b)      The planet closer to the star to take more time that the one farther away

c)      This observation would falsify his laws of planetary motion

d)     Both planets to necessarily take exactly the same time to complete an orbit

e)      The planet closer to the star to take less time that the one farther away

6.      Aristotelian cosmology

a)      Could be falsified by the single observation of a celestial object farther from Earth than the Moon and which would not orbit the Earth

b)      Was impossible to falsify

c)      Was heliocentric

d)     Could be falsified only by showing that all celestial bodies, including the Moon, do not orbit the Earth

7.      One important consequence of the Copernican theory was that

a)      It supported Aristotle’s idea that nature determines motion

b)      It demonstrated that the universe is not eternal

c)      It was able to predict eclipses for the first time in human history

d)     It was based on the hypothesis that natural motion  is determined by nature

e)      It demoted the Earth from the role as the center of the universe to that of just another planet circling the Sun.

8.      According to the geocentric hypothesis the motion of the Sun across the sky

a)      Is produced by the rotation of the Earth about its center

b)      Is an illusion: the Sun is really moving away from Earth due to is fiery nature

c)      Is due to a combination of a rotation of the Earth and its motion away from Earth due to its airy character

d)     It is, in fact, moving form East to West

e)      The Earth slides form West to East during the day and then back during the night

9.      The Keplerian theory

a)      Is applicable only to the solar system

b)      Shows that planets move in ellipses with the sun at one of the foci

c)      Argues that planets move in circles, but they appear  to move in ellipses due to the motion of the Earth itself

d)     Can be falsified only if all planets fail to move in ellipses around the Sun

e)      Cannot be falsified

10.   In Aristotle’s philosophy the universe must have a single center, this was a troublesome to the Church because

a)      The Church supported the heliocentric hypothesis

b)      If accepted, this conclusion would imply a limit on the powers of God

c)      It is explicitly contradicted in the Bible

d)     It led to polytheism