Astro_Test3

Newton’s law of gravity is F = M1 x M2 ÷ d2 How does the gravitational force between two objects change if the distance between them triples?

A. The force is 3 times greater.
B. The force does not change.
C. The force is 9 times greater.
D. The force is 3 times weaker.
E. The force is 9 times weaker.

Newton’s law of gravity is F = M1 x M2 ÷ d2. What is the force of gravity between two asteroids (M1 = 4 and M2 = 2) that are a distance d = 2 apart?

A. F = 8
B. F = 16
C. F = 2
D. F = 4

You apply a force to lift your body up when you step upon to a ladder. Which basic type of energy do you gain?

A. kinetic (motion)
B. potential (stored)
C. radiative (light)
D. thermal (heat)
E. none of the above

When you fall off the ladder you gain _____ energy and lose _____ energy.

A. thermal, potential
B. potential, kinetic
C. thermal, radiative
D. kinetic, thermal
E. kinetic, potential

When you get hit by a 95 mph pitched baseball, the ball _____ kinetic energy while you ___.

A. loses, gain potential energy
B. gains, lose potential energy
C. gains, lose kinetic energy
D. loses, gain kinetic energy

Does the batter gain all of the baseball’s kinetic energy?

A. yes
B. no

Consider a planet that orbits the Sun in an ellipse. We learned from Kepler that the planet’s velocity is ______

A. greatest at Rnear
B. least at Rnear
C. not enough info
D. greatest at Rfar

If the planet’s angular momentum = 36 when it is farthest from the Sun, what is its angular momentum when the it is nearest to the Sun?

A. is 12
B. is 108
C. is 72
D. is 36

The Moon’s orbit is an ellipse. When it is closer to the Earth its velocity is _____ and its total orbital energy is _______ when it is farther from the Earth.

A. smaller, the same as
B. larger, larger than
C. larger, the same as
D. larger, smaller than
E. smaller, smaller than

A piece of space debris that burns up in the atmosphere is called a ______ , while a piece of debris that makes it to the ground is called a ______ .

A. meteor, meteorite
B. comet, asteroid
C. meteor, asteroid
D. meteorite, meteor

The Asteroid Belt was once thought to be the remnants of a smashed planet between Mars and Jupiter. What is wrong with that hypothesis?

A. there is not enough total asteroid material
B. planets never get hit by other objects
C. there’s not enough room between Mars & Jupiter
D. asteroids & planets are made out of different stuff

How big of an object causes a typical ‘shooting star’?

A. a grain of sand or small pebble
B. a basketball
C. an object the size of a car
D. a big boulder

What would happen if a 10-km object impacted the Earth?

A. Cause widespread devastation and climate change.
B. Cause atmospheric explosion and small crater.
C. It would break up in the atmosphere causing a dramatic meteor shower but little damage.
D. Cause a mass extinction.

As NASA’s Mariner 10 passed by Venus, its speed increased (not from firing its engines). What must have happened?

A. Venus must have captured an asteroid at that time.
B. A gust of solar wind accelerated the spacecraft.
C. Mariner 10 must have dipped into the planet’s thick atmosphere.
D. Venus must have given a very tiny bit of its orbital energy to increase the orbital energy of Mariner 10.
E. Venus’ rotation must have sped up slightly.

Compare two baseballs you throw into the air with different forces. At their highest point in their path, the faster thrown ball will have ___ than the other.

A. less gravitational potential energy
B. more kinetic energy
C. less kinetic energy
D. more gravitational potential energy

Suppose 2 Kuiper comets are orbiting in nearly identical orbits, and they happen to pass close enough to each other to have their orbits changed by this gravitational encounter. If one comet moves into a new orbit closer to the Sun, what happens to the other comet?

A. It will move into an orbit farther from the Sun.
B. It will become vastly much colder.
C. It will also move closer to the Sun.
D. It will stay on its original orbit.

If all of the planets, moons, asteroids and Kuiper Belt comets & dwarf planets orbit the Sun in same direction and in the same (ecliptic) plane, why might the Oort Cloud comets orbit randomly from all directions?

A. They are fragments from a huge past explosion centered where the Sun is now.
B. They have all been ejected from the inner Solar Sys.
C. They formed at different time than the Solar Sys.
D. They formed outside of the Solar System.

Our inventory of possible impactors can be summed up as_____ comets with _____ average sizes than asteroids.

A. more, larger
B. more, smaller
C. less, larger
D. less, smaller

Thinking about our inventory of possible impactors, which type of 10 km object are we more likely to get hit by?

A. comet
B. meteorite
C. asteroid
D. meteor

Do all comets always have tails?

A. Yes, they always have tails, but they don’t all have the same size tail.
B. Yes, they are invisible until close enough to see.
C. No, only when they are close to the Sun because they are caused by the Solar Wind.
D. No, only Oort Cloud comets ever have tails.

The Denver news video described a spectacular meteor. According to the rules of motion in the Universe, why does the meteor “just fizzle away”?

A. They are like rockets shooting out hot gas that propels them through the sky.
B. They die and lose their light.
C. They are from an extinct constellation.
D. They are high speed particles feeling huge frictional forces resulting in some of their kinetic energy changing into thermal and radiative energy.

As a general rule, meteors come from ______ and meteorites come from ______ ?

A. asteroids, asteroids
B. asteroids, comets
C. comets, asteroids
D. comets, comets

A comet’s orbit will be disturbed when its _________ is changed by a __________ with another object.

A. orbital energy, gravitational encounter
B. rest-mass energy, gravitational encounter
C. orbital energy, heat exchange
D. mass, kinetic energy change

Which of the following is not a major pattern of motion in the Solar System?

A. The majority of comets orbit the Sun in the samedirection and roughly in the same plane.
B. Most large moons orbit in a plane that is alignedwith their planet’s equator.
C. All planets orbit the Sun in the same direction,(counterclockwise as viewed down from the north).
D. The Sun and most of the planets rotate in the samedirection in which the planets orbit the Sun.

The rings around planets in our Solar System are ____.

A. composed of many pieces of ice and rock.
B. actually atmospheric phenomena found in gas giant planets.
C. flat solid disks like a frisbee with a central hole.
D. made of many thin solid rings of different diameters.

What causes the volcanoes and ice geysers on some moons of planets?

A. Collisions with other moons.
B. Strong tidal forces from orbiting close to planet.
C. Scientists have no models for this process.
D. Recent heavy bombardment = many impacts.

Which one of the following is not among the recent discoveries made by our robotic exploration of the Solar System?

A. Strong evidence for liquid water outside of Earth.
B. Jupiter’s Great Red Spot is a violent hurricane.
C. The 4 big planets are gas giants with multiple moons.
D. Methane lakes on a distant moon.
E. Active volcanoes on distant moons.

Besides planets, the Solar System contains a swarm of smaller bodies that can be divided as follows:

A. small snowballs, large rocks
B. rocks close to Sun, snowballs far from Sun
C. smaller & far from Sun, larger & close to Sun
D. rocks close to Sun, rocks far from Sun
E. snowballs close to Sun, snowballs far from Sun

The inner planets are ____ while the outer planets are ______ and made mostly of ________.

A. small & rocky, large, gas & H compounds
B. small & rocky, large, rock & ice
C. small & icy, large, gas & H compounds
D. large & rocky, small, gas & H compounds
E. small & rocky, large, gas & metals

What would happen if a 10-km object impacted the Earth?

A. Cause widespread devastation and climate change.
B. Cause a mass extinction.
C. Cause atmospheric explosion and small crater.
D. It would break up in the atmosphere causing adramatic meteor shower but little damage.

As Mariner 10 passed by Venus, its speed increased (not from firing its engines). What must have happened?

A. Venus’ rotation must have sped up slightly.
B. Mariner 10 must have dipped into the planet’sthick atmosphere.
C. Venus must have given a very tiny bit of its orbital energy to increase the orbital energy of Mariner 10.
D. A gust of solar wind accelerated the spacecraft.
E. Venus must have captured an asteroid at that time.

The conservation of energy explains why a spacecraft gains orbital energy at the expense of the planet’s orbital energy. Why did planet & space craft exchange energy?

A. Because the spacecraft felt gravity from the planet.
B. both A & B
C. Because the planet felt gravity from the space craft.
D. Because an object moves at constant velocity unless acted on by an outside force.
E. Because of conservation of momentum.

To be classified as a planet, a Solar System object must meet three criteria:

A. only orbits the Sun
B. be massive enough so that gravity pulls it into aspherical (or ellipsoidal) shape
C. have cleared its neighborhood of small objects

Which of these criteria is not met by the Moon, so that it is not classified as a planet?

A. only orbits the Sun
B. have cleared its neighborhood of small objects
C. be massive enough so that gravity pulls it into aspherical (or ellipsoidal) shape

Which of these criteria is not met by Pluto?

Why does the cloud heat up as it collapses?

A. Nuclear fusion in the core converts rest-mass energy to heat.
B. Gravitational potential energy is converted into heat (kinetic) energy.
C. The gas cloud is heated up by nearby young stars.
D. Friction causes gas cloud particles to warm up.

Why does the cloud spin faster as it collapses?

A. Conservation of angular momentum tells us that the spin must speed up as the size shrinks.
B. As gas cloud heats up it gains kinetic energy meaning the gas particles move in faster circles.
C. The gas cloud loses radiative energy (glows) which is balanced by gain in orbital energy.

If water exists in some form in each region (1,2,3), which region around the Sun would you most expect to find water in its solid phase?

A. 1
B. 2
C. 3 coldest region for ice

In this face-on view of the proto-planetary disk, which region has its entire composition only in gas form?

A. only 1
B. all 1, 2 & 3
C. both 2 & 3
D. only 2
E. only 3

Why do we think the inner (terrestrial) planets became more dense than the outer planets?

A. The inner nebula was so hot that they formed from only metals and rocks with high melting points.
B. The rotating disk in which the planets formed spun lighter elements outward by centrifugal force.
C. In the collapsing solar nebula, denser materials sank toward the center.
D. The Sun’s gravity pulled denser materials toward the center.

Why could the outer (Jovian) planets grow to be much larger than the terrestrial planets?

A. They were far enough away to escape the heavy bombardment that battered the early solar system.
B. They were further from the Sun and gravity was weaker.
C. They formed where the temperature was low enough to allow H compounds to also condense.

How much of Solar Nebula’s mass winds up in the proto-planetary disk (material planets form from)?

A. 2%
B. 0.1%
C. 10%
D. 1%

of the proto-planetary disk, which region has a composition of 98% H, He + 2% other?

A. all 1, 2 & 3
B. only 1
C. only 3
D. only 2
E. both 2 & 3

During accretion, what happens to the total number of particles as time goes on?

A. The number stays the same.
B. The number increases.
C. The number decreases.

A period of intense accretion has built some rocky inner planets and some ice+rock outer planets.What is left over from the proto-planetary disk?

A. Nothing.
B. Some leftover planetesimals.
C. Some leftover planetesimals and H,He gas.

Where do asteroids and comets come from?

A. They are the result of early extra planets that broke apart.
B. They are escaped moons.
C. Asteroids are leftover planetesimals from the outer Solar System, comets are inner leftovers.
D. Asteroids are leftover planetesimals from the inner Solar System, comets are outer leftovers.

Compare the protoplanetary disk where Earth and Jupiter are forming. The mass of proto-Jupiter is _____ and the nearby gas is _____ compared with proto-Earth.

A. smaller, warmer
B. larger, cooler
C. larger, warmer
D. smaller, cooler

The large mass of the proto-Jupiter means it has a _____ gravitational pull on the nearby _____ moving gas with low kinetic energy.

A. strong, slow
B. strong, fast
C. weak, fast
D. weak, slow

The main steps of the formation sequence for a rocky planet are:
+ accretion of the planetesimals
+ collapse of the solar nebula
+ clearing of debris
+ condensation of solids from nebula
Which is the correct order of these steps (start to finish)?

How would the Solar System be different if the initial nebula was half as hot?

A. There would be no comets.
B. There would be no asteroids.
C. Gas giants would have formed closer to the Sun.
D. Rocky planets would be larger.

The theory of solar system formation is not supported by which fact?

A. Most planets rotate in the same direction that they orbit the Sun.
B. All eight planets orbit in the same plane.
C. Equal numbers of rocky and gas giant planets.
D. All eight planets orbit in the same direction.

Using the Doppler method to detect exoplanets, astronomers measure the speed of the _______ .

A. Sun
B. exoplanet
C. Earth
D. star

Suppose you found a star with the same mass as the Sun that was wobbling with a period of 2 years. What would you conclude?

A. It has a planet orbiting at exactly one AU.
B. It has a planet orbiting at less than one Earth/Sun distance (1 AU).
C. It has a planet orbiting at greater than one AU.
D. It has a planet, but we do not have enough information to know its orbital distance.

Which of the following is the origin of almost all large moons orbiting the gas giant planets?

A. They were formed by giant impacts.
B. They were captured comets.
C. They were captured asteroids.
D. They were formed by accretion of material in a disk around the planet.
E. They were captured planets.

The composition of the Solar Nebula was very similar to the composition today of...

A. the atmospheres of Jupiter and Saturn.
B. the core of Earth.
C. the atmosphere of Saturn’s large moon Titan.
D. the atmosphere of Earth.
E. the surface of Pluto.

Could a planetary system like ours have formed with the first generation of stars after the Big Bang?

A. No, there would not have been enough rock and metals to form terrestrial planets.
B. Possibly, there is no physical reason why not.
C. No, there would not have been enough time.
D. No, the expansion of the Universe would have torn the planetary system apart.

Approximately how many exoplanets have been confirmed to date?

A. 550
B. 50
C. 55,000
D. 5000

The existence of exoplanets is typically known through...

A. effects on the parent star
B. transits (planets eclipsing some of star light)
C. direct imaging
D. theoretical justifications

Based on our current theory of Earth’s formation, the water we drink came from...

A. comets that impacted the Earth.
B. material left behind from the giant impact that formed the moon.
C. ice that condensed from the Solar Nebula in the region where the Earth formed.
D. chemical reactions that occurred in the Earth’s crust after formation.