Exam 2
The gravitational attraction of the Earth for other objects,
is smaller for objects farther from the earth but never vanishes completely
Law of Inertia states that a moving object will
keep moving if no force acts on it
The Lunar Maria are thought to have been caused by ancient
lava flows from large impacts
As viewed from the star Polaris, Venus
rotates clockwise and goes around the Sun counter-clockwise
Viking 1 and 2 were sent to explore
Mars
Suppose that you try to lift an object by exerting an upward force of 5 Newtons on it. If gravity exerts a force of 10 Newtons downward on the object, what is the total force on the object?
5 newtons downward
If you are told that a 20 kilogram object is raised by 10 meters, you know that
The mass of the object is 20 kg
Water ice can be found on all but one of these planets. Which one has no ice?
Venus
Which of the following planets has no magnetic field of any kind?
Venus
Which of the following planets has no moons at all?
Venus
Which of the following planets or moons has an atmosphere with about 90 times the surface pressure of Earth's
Venus
On Earth, you might find a temperature of 59°F on a Spring or Fall day in the temperate zone. On Mars, you might expect that temperature
at noon near the equator
For a planet to have substantial amounts of liquid water on its surface, it must have
atmospheric pressure above the triple point of water
The discovery that there is water ice on the Moon has motivated many nations to launch Moon missions because it
could make a Moon base possible
The circular structures on the surface of the Moon are the result of
impacts
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
in the plane of the earths equator
Which of the following objects has no magnetic field at all?
Earth's moon
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 5000kg (including the sail) and sunlight exerts a total force of 5N on the sail. What will be the acceleration of the spacecraft?
.001 m/s A = F/M
An ion rocket engine produces 50 Newtons of thrust. What acceleration can it give to a space probe with a mass of 10,000kg?
.005 m/s
The average radius of the Earth's orbit is
1.0 AU
Suppose that you try to lift an object by exerting an upward force of 5 Newtons on it. If gravity exerts a force of 20 Newtons downward on the object, what is the total force on the object?
15 Newtons downward
The first successful soft landing on the Moon was Surveyor 1 in
1966
Mercury rotates so that its sidereal day lasts for
2/3 of a complete orbit around the sun
If the planets are numbered from 1 to 8, going outward from the Sun, the planet Mars is number
4
What total force will cause an object with a mass of 1kg to gain 5 meters per second every second?
5 Newtons
What total force will cause an object with a mass of 50kg to gain 1 meter per second every second?
50 Newtons F= MxA
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?
5200 KG/M
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?
5200 kg/m
Which of the following types of objects include things that could reasonably be described as "flying rocks" or, for the larger ones, "flying mountains?"
Asteroids
Which of these Mars rovers has been operating on the surface of Mars for six years so far (as of 2018)
Curiosity
Galileo predicted that dropping a wooden ball and an iron ball at exactly the same time would result in them hitting the ground at the same time, so long as air friction was negligible. When he actually did the experiment, the balls hit the ground very close together, but sometimes the wooden ball hit first and sometimes the iron one hit first. If we repeat his experiment today, we find exactly the same thing. Which of the following conclusions is appropriate?
Galileo really did the experiment
Galileo predicted that dropping a wooden ball and an iron ball at exactly the same time would result in them hitting the ground at the same time, so long as air friction was negligible. When he actually did the experiment, the balls hit the ground very close together, but sometimes the wooden ball hit first and sometimes the iron one hit first. If we repeat his experiment today, we find exactly the same thing. Which of the following conclusions is appropriate?
Galileo's theory was not disproven because the slight differences can be explained by defects in the experiment.
The International Space Station (ISS) 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 raise it to a new circular orbit, farther from the surface by having a rocket give it one or more short boosts. Which of the following schemes will work?
Increase its speed to 6 miles per second to put it on a rising path and give it another speed boost when its distance from the Earth stops increasing.
Which of the following planets has a moon that rises in the West?
Mars
Which of these planets has a solar day that is very close to an Earth day in length?
Mars
Which of these planets is the farthest from the Sun?
Mars
Which of the following planets can be said to have almost no atmosphere?
Mercury
Which of these Mars rovers has been operating on the surface of Mars for fourteen years so far (as of 2018)?
Opportunity
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
It is currently thought that moons typically do not form near
Terrestrial planets such as Earth and Mars
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
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
The capture theory was dropped partly because it predicts that the Moon should have hydrated rocks and it does not.
An astronomical unit is
The distance from the Earth to 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 that object is 20 Newtons
A book, weighing 10 Newtons, sits on a table. Which of the following pairs of forces is an action-reaction pair?
The force that the book exerts on the table and the force that the table exerts on the book
When Newton calculated the magnitude of the acceleration of Earth's Moon relative to the Earth, and compared it to the acceleration of falling objects on the surface of the Earth, he found that
The moon's acceleration was smaller
When Newton calculated the magnitude of the acceleration of Earth's Moon relative to the Earth, and compared it to the acceleration of falling objects on the surface of the Earth, he found that
The moons acceleration is smaller
A lunar crater is best described as
a circular ring wall surrounding a flat area
Which of the following objects would be most likely to have a long elliptical orbit that takes it from far outside the orbit of Mars to a close approach to the Sun?
a comet
the ancient greeks thought that
a heavy object should fall faster than a lighter object because the heavy object is pulled down with more force
In comparison to Kepler's Laws of Planetary Motion, Newton's theory of Universal Gravitation predicted
almost the same motions but with corrections
Mars has
an atmosphere of carbon dioxide with about 1% the surface pressure of Earth's
On the present surface of Mars, water has been confirmed to exist
as ice at the poles and water vapor in the atmosphere
Space probes often use gravitational slingshot maneuvers. The main purpose of these maneuvers is to
change the direction and speed of the probe without using rockets
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
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
Which of the following objects would be most likely to have a long elliptical orbit that takes it from far outside the orbit of Mars to a close approach to the Sun?
comet
Apollo 11 made the first
crewed landing on the moon
The magnetic field of Mars is
essentially zero
Suppose that a spacecraft is in a roughly circular orbit near the surface of the Earth, moving at around 5 miles per second. Suppose the spacecraft flips over backwards and fires its rocket engine to slow its speed to 4.96 miles per second. The spacecraft will then
follow an ellipse that descends a bit and then rises again
Suppose that a spacecraft is in a roughly circular orbit near the surface of the Earth, moving at around 5 miles per second. Suppose the spacecraft flips over backwards and fires its rocket engine to slow its speed to 4.96 miles per second. The spacecraft will then
follow an ellipse that descends and then rises again
Freely falling objects with different masses fall with the same acceleration because
gravity exerts more force on the more massive object
Mercury rotates so that it
has a solar day that last for two complete orbits around the Sun.
The force of gravity explains
how the tides work but not how lightning works.
The statement that lunar material is much "dryer" than Earth material refers to the absence of
hydrated minerals
The Earth's Moon
is 1/4 the size of the Earth, which is unusually large for a moon.
The Moon's orbit around the Earth
is elliptical enough to give us an annular solar eclipse when the Moon is near its apogee.
The gravitational attraction of the Earth for other objects
is smaller for objects farther from the Earth but never vanishes entirely
Compared to the rest of the Lunar surface, the Lunar Maria are
lower and younger
When the rocket engine in a spaceship stops firing, the spaceship keeps moving because
no force stops it
The observed magnetic field of Mercury is surprising because it was expected to have
no magnetic field at all because it rotates so slowly.
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
The phase diagram for water is presented on a graph with axes for temperature and
pressure
The Earth's magnetic field plays an essential role in
protecting the earth from charged particles from the sun
The current model for the way that planets acquire magnetic fields requires which of the following combinations of things?
rotation and a core that contains a liquid electrical conductor
At present (within the last few hundred years) the orbit of the Earth around the Sun is
slightly elliptical so that the intensity of the sun varies by 6%
A full cycle of day and night on Mars is called a `sol.' In terms of 24 hour Earth days, a Martian sol is
slightly longer than one Earth day
An astronomical unit is defined to be
the average distance from Earth to the Sun
Since the last Apollo mission to the Moon and the last Soviet LUNA sample-return mission
spacecraft began to be sent there again by 1994
The Soviet Union had a secret program to put the first human on the Moon. This program
test launched their Moon Rocket several times, but it blew up each time
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
You are standing in an elevator that is accelerating upward at 1m/s². Which of the following pairs of forces is an action-reaction pair that have to be exactly equal and opposite to each other?
the force that the floor of the elevator exerts on you and the force that you exert on the floor of the elevator
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, Aristotle would predict that
the heavier object would hit the ground long before the lighter one
The Moon rotates on its axis so that it always keeps
the same side (its far side) pointed away from the earth
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
In Newton's theory of gravity, everything is attracted
to every other object in the universe
The Moon rotates on its axis so that it always keeps the same side
toward the Earth
A planet that is following Kepler's Laws, accelerates
towards the sun
The Law of Inertia says that if an object is not acted on by any outside force, its acceleration
will always be zero
