Astronomy Exam 2 - ALL QUESTIONS (some modified)
An ion rocket engine produces 5 Newtons of thrust. What acceleration can it give to a space probe with a mass of 10,000kg?
0.0005 m/s2
The ancient greeks connected the force exerted on an object to the object's
5.1 Speed
What total force will cause an object with a mass of 10kg to gain 5 meters per second every second?
50 Newtons
The density of water is 1000kg/m3, the density of rock is about 3000kg/m3, and the density of iron is 7800kg/m3. Which of the following densities is closest to the average density of the Earth?
5200kg/m3
Which of the following planets has the most extreme range of temperatures
7.1 Mercury
Suppose that you drop two objects from the same height at the same time. Both objects are heavy enough to be unaffected by air resistance and one object is twice as heavy. Who predicted that the heavier object would hit the ground long before the lighter one?
Aristotle
According to Newton, every object is...
Attracted to every other object in the universe.
The shortest Earth-Sun distance happens in the month of
January
Which of the following objects has no overall magnetic field except for small regions due to magnetized ore deposits?
Mars
Which of these planets has a solar day that is very close to an Earth day in length?
Mars
The first space probe to place a robotic rover on the surface of Mars was
Pathfinder
The first space probes to land on another planet were from the
Russian Venera series
A rocket is in a roughly circular orbit near the surface of the Earth, moving at around 5 miles per second. Suppose that it is desired to lower it to a new circular orbit, slightly closer to the surface. The rocket flips over and fires its main rocket engine in a short burst to slow its speed to 4.96 miles per second. What must it do next? -
Slow its speed again by a bit when its distance from the Earth stops decreasing.
Our Sun sends out intense streams of charged particle radiation. The radiation is prevented from hitting the Earth's atmosphere by
The Earth's magnetic field
Galileo's used most of the same tools of thought that the ancient greeks had used. Which of the following approaches did use that would not have seemed natural to the ancient Greeks?
active construction of simplified experiments.
Kepler's Laws of planetary motion were originally obtained by fitting accurate observations. Newton explained those laws by a force that
acts on all objects.
Venus has
an atmosphere of carbon dioxide with about 90 times the surface pressure of Earth's
The absence of a magnetic field of Venus is
as expected because the planet rotates so slowly
On the present surface of Mars, water has been confirmed to exist
as ice at the poles and water vapor in the atmosphere.
Kepler's Laws of planetary motion were originally obtained by fitting accurate observations. Newton explained those laws by a force that acts on each planet. The force that specifically explains Kepler's Laws
attracts each planet to the sun
Suppose that you drop two objects from the same height at the same time. Both objects are heavy enough to be unaffected by air resistance. If one object is twice as heavy as the other, Galileo predicted that
both objects would hit the ground at the same time.
The currently accepted theory of how the Moon formed is the
collision theory
When a space probe uses a gravitational slingshot maneuver, it
comes close to a planet to change the probe's speed and direction
Most Kuiper Belt Objects are similar in composition to
comets
Which of the following types of object could reasonably be described as dirty snowballs or, for the larger ones, flying icebergs?
comets
Relative to the distant stars, Mercury
completes 1.5 rotations each time it orbits the Sun.
Comets usually follow orbits which are
elliptical with aphelia far outside the orbit of Mars.
A rocket that leaves the Earth's atmosphere at a speed of 8 miles per second will -
escape from the Earth's gravity forever.
A rocket that leaves the Earth's atmosphere at a speed of 8 miles per second will
escape from the Earthís gravity forever.
The magnetic field of Earth's Moon is
essentially zero
The Earth's Moon
is 1/4 the size of the Earth, which is unusually large for a moon
The Law of Inertia says that if an object is not acted on by any outside force
its speed and direction of motion will not change.
A unit of mass
kilogram
When a bullet is fired from a gun, the bullet keeps moving after it leaves the gun barrel because
no force stops it
When the rocket engine in a spaceship stops firing, the spaceship keeps moving because -
no force stops it.
For an object that is moving along a straight path, the acceleration is
the change in the object's speed divided by the time it takes.
A bazooka is actually a small rocket-launcher. The reason a bazooka does not have a recoil is that
the force on the rocket is exerted by the rocket exhaust and not by the launcher.
A bazooka is actually a small rocket-launcher. The reason a bazooka does not have a recoil is that
the force on the rocket is exerted by the rocket exhaust and not by the launcher. e on the rocket is exerted by the rocket exhaust and not by the launcher.
In comparison to Kepler's Laws of Planetary Motion, Newton's theory of Universal Gravitation predicted almost the same motions, but with small corrections due to
the gravitational attractions between different planets.
Mercury rotates so that its sidereal day lasts for
two thirds of a complete orbit around the Sun.
A comet that is passing close to the Sun will have a tail that is most likely
very long because sunlight is pushing on it.
Water ice can be found on all but one of these planets. Which one has no ice?
Venus
What planet has a high surface temperature?
Venus
Which of the following objects has no magnetic field but probably does have a large iron core?
Venus
Which of the following planets has no moons at all
Venus
From Polaris, how does Venus rotate around the sun?
Venus rotates clockwise and goes around the sun counter clockwise
Galileo's used most of the same tools of thought that the ancient Greeks had used. Which of the following approaches did use that would not have seemed natural to the ancient Greeks?
active construction of simplified experiments.
Relative to the distant stars, Venus
completes less than one full rotation each time it orbits the Sun
Satellites such as the International Space Station orbit above most of the Earth's atmosphere because -
there is no air friction to slow the satellite down.
A planet whose atmospheric pressure is exactly at the triple point of water and whose surface temperature has a range that includes the triple point will have
water as ice or vapor, depending on the temperature
The orbit of mars around the sun is
Elliptical and the sunlight varies by 40%
A solar sail is a large sheet of light-reflecting plastic spread on an extremely low-mass framework and attached to a spacecraft. Sunlight exerts a force on the sail and moves the spacecraft. Suppose the spacecraft has a total mass of 100kg (including the sail) and sunlight exerts a total force of 2N on the sail. What will be the acceleration of the spacecraft? -
0.02m/s².
The average radius of the Earth's orbit is
1.0 AU
What total force will cause an object with a mass of 1kg to gain 10 meters per second every second?
10 Newtons.
Suppose that you lift an object by exerting an upward force of 22 Newtons on it. If gravity exerts a force of 10 Newtons downward on the object, what is the total force on the object?
12 Newtons
Suppose that you lift an object by exerting an upward force of 22 Newtons on it. If gravity exerts a force of 10 Newtons downward on the object, what is the total force on the object?
12 Newtons.
The first human landing on the Moon was Apollo 11 in
1969
If the planets are numbered from 1 to 8, going outward from the Sun, the planet Earth is number
3
Suppose that you drop a solid iron ball and a hollow iron ball, both the exact same diameter, from the same height at the same time. Aristotle would predict that
5.1 the solid ball would hit the ground long before the hollow ball.
Galileo had no difficulty accounting for the motion of a thrown object because
5.2 no force was needed to keep the object moving
Galileo was the original discoverer of
5.3 Newton's First Law of Motion.
For a planet that is following Kepler's Laws, the magnitude of the planet's acceleration is
5.4 inversely proportional to the square of the planet's distance from the Sun.
An astronomical unit is defined to be
6.1 the average distance from the Earth to the Sun.
The density of water is 1000kg/m³, the density of rock is about 3000kg/m³, and the density of iron is 7800kg/m³. Which of the following densities is closest to the average density of the Earth?
6.2 5200kg/m³
The density of water is 1000kg/m³, the density of rock is about 3000kg/m³, and the density of iron is 7800kg/m³. Which of the following densities is closest to the average density of Jupiter?
6.3 1200kg/m³
Which of the following types of objects include things that could reasonably be described as "flying rocks" or, for the larger ones, "flying mountains?" -
6.4 Asteroids.
Which of the following types of object could reasonably be described as "dirty snowballs" or, for the larger ones, "flying icebergs?"
6.5 Comets.
If the planets are numbered from 1 to 8, going outward from the Sun, the planet Uranus is number
7
When a space probe uses a gravitational slingshot maneuver, it
7.1 comes close to a planet to change the probe's speed and direction.
Which planets or moon has an atmosphere whose temperature and pressure permit all three forms of water?
7.3 Earth
Changes in the intensity of sunlight due to shifts in both the Earth's orbit and rotation axis cause
7.3 Milankovich cycles.
Besides the object that we call `The Moon,' Earth has
7.3 about 500 active artificial satellites and several thousand inactive ones.
Our Sun sends out intense streams of charged particle radiation. Most of these charged particles
7.3 are trapped by the Earth's magnetic field for a while and then strike the atmosphere over the poles.
Earth's orbit is currently elliptical enough to make the intensity of sunlight vary by 6 percent. The largest Earth-Sun distance (and lowest intensity sunlight) occurs
7.3 every July.
The number of moons of Mars is
7.4 2
Which of these Mars rovers has been operating on the surface of Mars for six years so far (as of 2018)
7.4 Curiosity
Viking 1 and 2 were sent to explore
7.4 Mars
Which of the following planets has a moon that rises in the West?
7.4 Mars
Which of these Mars rovers has been operating on the surface of Mars for fourteen years so far (as of 2018)?
7.4 Opportunity
The first space probe to test the air-bag landing system was
7.4 Pathfinder
The range of temperatures on Mars is
7.4 Similar to those in Antarctica
Mars has
7.4 an atmosphere of carbon dioxide with about 1% the surface pressure of Earth's.
In the present surface environment of Mars, water has been confirmed to exist
7.4 as short-lived spurts of liquid water.
Mars' orbit is currently (within the last few hundred years)
7.4 elliptical enough to make the intensity of sunlight vary by 40 percent.
The magnetic field of Mars is
7.4 essentially zero
Mars has a solar day
7.4 that is very close to an Earth day in length.
The circular structures on the surface of the Moon are the result of
8.1 Impacts
The side of the Moon that faces away from the Earth
8.1 Only has a few Lunar Maria
The magnetic field of Earth's Moon is
8.1 essentially zero.
The Moon's orbit around the Earth
8.1 is elliptical enough to give us an annular solar eclipse when the Moon is near its apogee.
The Lunar Maria are thought to have been caused by ancient
8.1 lava flows from large impacts.
The Moon rotates on its axis so that it always keeps
8.1 the same side (its far side) pointed away from the Earth.
The capture theory, in which our Moon forms separately and is captured by the Earth,became popular when computer models showed that such a capture would have been possible.
8.2 The capture theory was dropped because it predicts that the Moon should have hydrated rocks and it does not.
Hydrated minerals on the Moon
8.2 are almost completely absent.
A model in which the Moon forms from the same rotating cloud of gas and dust as the Earth would predict that the Moon's orbit should be
8.2 in the plane of the Earth's equator.
The first successful soft landing on the Moon was Surveyor 1 in
8.3 1966
Apollo 8 made the first
8.3 manned orbit of the moon
The Soviet Union had a secret program to put the first human on the Moon. This program
8.3 test launched their Moon Rocket several times, but it blew up each time.
Since 1990, the major spacefaring nations, Europe, China, Russia, Japan, India, and the U.S., have begun to return to the Moon. As of 2009, of these six space programs
8.4 all except Russia have sent probes or orbiters to the Moon.
The discovery that there is water ice on the Moon has motivated many nations to launch Moon missions because it
8.4 could make a Moon base possible.
Call the time it takes Venus to orbit the Sun a "Venusian year." Call the time it takes Venus to rotate once on its axis relative to the distant stars a "Venusian sidereal day." Which of the following statements about these two time periods is true?
A Venusian year is shorter than a Venusian sidereal day.
A linear crater is BEST described as
A circular ring wall around a flat area
How long does is take for the moon to rotate on its axis
A sidereal month
A planet with a large liquid base should...
Have a magnetic field IF it moves fast enough.
What is the magnitude of a planet's acceleration?
It is inversely proportional to the square of the planet's distance from the sun.
How does Mercury rotate around the sun?
It rotates once every 2 orbits around the sun.
The Apollo program was thought to be part of a "race to the Moon" with the Soviet Union. Actually
It was a close race. The Soviets actually built a Moon rocket and tested it
Which of the following types of object could reasonably be described as "dirty snowballs" or, for the larger ones, "flying icebergs?"
Kuiper Belt Objects.
The Asteroid Belt is between the orbits of
Mars and Jupiter.
The angle between the rotation axis of a planet and the perpendicular to the plane of its orbit is called its "axial tilt." Which of these planets has an axial tilt that is less than one degree?
Mercury
Which of the following planets can be said to have almost no atmosphere?
Mercury
Galieo says that an object will stay in motion as long as...
No force acts on it
Which of these Moons rises in the West as seen from its primary planet?
Phobos
Compare the magnitude of the acceleration of Earth's Moon to the acceleration of falling objects on the surface of the Earth
The Moon's acceleration is smaller.
Why couldn't we just fly a a Space Shuttle to the Moon for at least a fly-by?
The Space Shuttle did not have enough fuel to reach escape velocity
Why couldn't we just fly a Space Shuttle to the Moon for at least a fly-by?
The Space Shuttle did not have enough fuel to reach escape velocity.
Why don't we just shoot all of our really nasty waste products into the Sun where they could not possibly bother anyone?
The Sun is actually the hardest part of the Solar System to get to from here.
A motorcycle is accelerating from rest. Which of the following pairs of forces is an action-reaction pair
The force of the motorcycle on the road and the force of the road on the motorcycle.
Which of the following circumstances would suggest that a rotating planet contains a core of liquid iron?
The planet is much denser than rock and has a magnetic field.
Law of Inertia: if an object is not affected by an outside source...
The speed nor direction will change
An atmosphere with about 90 times the surface pressure of Earth's is found on the surface of
Venus
What is a Van Allen Belt?
Where the Earth's magnetic field traps charged particles from the sun.
Is the earth's moon larger than we would expect?
Yes, it is 1/4 the size of Earth
It is expected that a normal Jovian planet, with no accidental encounters that could add or subtract moons, should have
a family of moons, all orbiting in the plane of the planets equator.
The surface magnetic field of Mercury is
about 1% of the Earth's magnetic field
So far (as of 2008), the planet Venus has been visited by
about 20 successful space probes.
At present (within the last few hundred years), the distance from the Earth to the Sun
changes enough to make the intensity of sunlight vary by 6 percent
Milankovich cycles refer to
changes in the intensity of sunlight due to shifts in both the Earth's orbit and rotation axis.
The impacts of large objects on the surface of the Moon have caused
craters
The Curiosity Mars rover
has been operating on Mars for six years so far (as of 2018)
Our current understanding of how planets acquire magnetic fields suggests that a planet with a large liquid iron core will
have a magnetic field if it rotates fast enough.
The gravitational attraction of the Earth for other objects,
is smaller for objects farther from the Earth but never vanishes entirely.
The Moon's orbit
is somewhat tilted relative to the plane of the Earth's equator.
Compared to the rest of the Lunar surface, the Lunar Maria are
lower and younger
The statement that the acceleration of an object is zero implies that the object
moves along a straight path with constant speed.
It is expected that a normal terrestrial planet, with no accidental encounters that could add or subtract moons, should have
no moon.
It is expected that a normal terrestrial planet, with no accidental encounters that could add or subtract moons, should have
no moons
When Newton's Laws were applied to predict the exact motion of the planet Uranus, the prediction failed to agree with very precise measurements. This failure led to the discovery
of the Planet Neptune.
Newton's Universal Law of Gravity explains all of the following things.
planetary motion, the motion of the Moon around the Earth, how objects fall on Earth, ocean tides.
Aristotle said that a moving earthly or mundane object with nothing pushing or pulling on it will always
slow down and stop
What is the motion of the Earth and Moon according to Newton's Theory
the Earth and Moon move around their center of mass, which, in turn, goes around the Sun.
If you are told that an object that weighs 20 Newtons is raised a distance of 10 meters, you know that.
the force of gravity on the object is 20 Newtons
If you are told that an object that weighs 20 Newtons is raised a distance of 10 meters, you know that.
the force of gravity on the object is 20 Newtons.
Suppose that an object with a mass of one kilogram and an object with a mass of two kilograms are both in free fall near the Earth's surface. As compared to the one kilogram object, the two kilogram object accelerates
the same because gravity pulls on it twice as strongly and it has twice the inertia.
The Moon rotates on its axis so that it always keeps
the same side (its far side) pointed away from the Earth
A planet that is following Kepler's Laws, accelerates
toward the sun
