PSC 101 Practice Exam 2: Planetary Motion, Gravity, and Astronomy

Does the desk exert a force upwards on the Scantron sheet?

Yes

How can an astronaut return to the space shuttle if their life-line breaks?

Using locomotion of your arms and legs, 'swim' through space back to the ship.

How long would it take a planet 2 AU from the sun to orbit once?

2 years

If the distance between two objects tripled, what would happen to the gravity?

1/9 of the original

If there were another planet between Saturn and Uranus, which statement would be true?

Its 'year' would be longer than Earth's.

In what order did Aristotle, Ptolemy, Copernicus, Galileo, and Newton live?

Aristotle, Ptolemy, Copernicus, Galileo, Newton

Is it true that Polaris is always at your zenith?

False

What did Newton show about orbits?

Things can orbit in circles, ellipses, parabolas, and hyperbolas.

What falls at Point A on the celestial sphere?

Polaris

What happens to a pipe released from the lips of an engineer on a falling train?

It will fall to the floor.

What happens when a heavy anvil and a feather are dropped on the moon?

They will impact the lunar surface at the same time.

What is D (the sun's path) called?

Ecliptic

What is Point A on the celestial sphere called?

North Celestial Pole

What is Point B on the celestial sphere called?

South Celestial Pole

What is Point C on the celestial sphere?

Celestial Equator

What is the point at which the Earth is closest to the Sun called?

Perihelion

What makes Polaris unique?

It remains stationary.

What would Eratosthenes calculate the circumference of the Earth as if the angular distance was 20 degrees?

6664 km

When does a force of gravitation exist?

Between any two objects.

When was the telescope invented?

1608

When was Thuban the North Star prior to 4500 B.C.E.?

In the year 21,500 B.C.E.

Which planets would it be impossible to see from Mars at midnight?

Mercury and Venus

Which statement accurately describes the orbital motions of the planets?

They sweep out equal areas in equal times.

Who formulated the laws of planetary motion from Tycho's data?

Kepler

Who was the first astronomer to use the telescope?

Galileo

Why are astronauts on the Moon considered weightless?

False because the Moon exerts a gravitational force on their bodies.

Why do objects in the heavens behave differently from those on Earth according to Aristotle?

They are made of a different element; they are perfect.

Why do planets move retrograde in the sky?

They are viewed from the Earth, which is also moving, but at a different rate.

Why do things 'float' in the space shuttle?

Everything on the space shuttle is falling freely about the Earth.

Why was the geocentric model accepted for so long?

It appealed to 'common sense'.