13-14 physics – Flashcards

Unlock all answers in this set

Unlock answers
question
The orbital speed for a satellite orbiting very close to Earth's surface is
answer
8000 m/s
question
The reason satellites orbit Earth at least 150 km above the surface is to
answer
be above Earth's atmosphere
question
The speed of a satellite in a circular orbit is
answer
constant
question
The speed of a satellite in an elliptical orbit is
answer
not constant
question
A period of a satellite is
answer
defined as the time for a satellite to make one complete revolution around Earth
question
The higher a satellite is,
answer
the less speed is and longer its period is
question
A circle is a special case of
answer
an ellipse
question
The circular orbit of a satellite orbiting Earth is characterized by constant
answer
speed, radius, magnitude of acceleration
question
The fastest moving planet in a solar system is
answer
the planet nearest the sun
question
Pluto takes a longer time to travel around the sun than Earth takes because Pluto
answer
has farther to go and goes slower
question
An object is placed exactly halfway between Earth and the moon. The object will fall toward
answer
Earth
question
A projectile is fired vertically from the surface of Earth as 10 km/s. The projectile will
answer
rise and then fall back to Earth's surface
question
A vertically oriented rocker that maintains a continuous upward velocity of 8 km/s will
answer
escape Earth
question
The Earlybird communications satellite hovers over the same point on Earth's equator indefinitely. This is because
answer
its orbital period is 24 period hours
question
A satellite near Earth makes a full circle in about an hour and a half. How long would it take a satellite located as far away as the moon to orbit Earth?
answer
about 28 days
question
Compared to the period of a satellite in orbit close to Earth, the period of a satellite in orbit far from Earth is
answer
longer
question
Where does a satellite in an elliptical orbit have the greatest kinetic energy?
answer
at the point closest to the planet
question
Where does a satellite in a circular orbit have the greatest kinetic energy?
answer
anywhere- its kinetic energy is constant
question
What remains constant for a satellite in an elliptical orbit?
answer
its total energy
question
Escape speed from the surface of Earth is about
answer
11.2 km/s
question
The curvature of Earth is such that for every 8000m tangent to the surface, the surface drops about
answer
5 m
question
Minimal orbital speed about Earth is approximately 8 km/s. Minimal orbital speed about the moon would
answer
less than 8 km/s
question
When in orbit, a satellite such as the space shuttle is
answer
simply a projectile
question
If you could throw a baseball horizontally at a speed of 8 km/s and if there were no air drag and nothing to stop it,
answer
it would orbit Earth
question
As a satellite is moving in orbit around the Earth, the sum of the kinetic energy and potential energy everywhere is
answer
constant
question
Newton hypothesized that the moon
answer
all of the above
question
If the mass of Earth increased, with no change in radius, your weight would
answer
increase also
question
If the radius of Earth decreased, with no change in mass, your weight would
answer
increase
question
If Earth's mass decreased to one half its original mass, with no change in radius, then your weight would
answer
decrease to one half your original weight
question
The gravitational force between two massive spheres
answer
all of the above
question
A very massive object A and a less massive object B move toward each other under the influence of mutual gravitation. Which force, if either, is greater?
answer
both forces are the same
question
Two objects move toward each other because of gravitational attraction. As the objects get closer and closer the force between them
answer
increases
question
Suppose the gravitational force between two massive spheres is 100 N. If the distance between the sphere doubled, what is the force between the masses?
answer
25 N
question
By noticing that Uranus's orbit is perturbed and by using the law of gravitation, two astronomers independently discovered
answer
Neptune
question
The force of gravity on you is greatest when you are standing
answer
on Earth's surface
question
The reason the moon does not fall into Earth is that
answer
the moon has a sufficiently large orbital speed
question
A lunar month is about 28 days. If the moon were closer to Earth than it is now, the lunar month would be
answer
less than 28 days
question
Each of us weighs a tiny bit less on the ground floor of a skyscraper than we do on the top floor. One reason for this is that
answer
the mass of the building attracts you upward slightly
question
A planet has half the mass of the Earth and half the radius. Compared to its weight on Earth, an apple on this planet would weigh
answer
twice as much
question
Consider the gravitational force between Earth and a meteor in outer space. If the meteor moves so its distance from the Earths center doubles, the gravitational force on the meteor will be
answer
one quarter
question
Which is greater, the gravitational force between Earth and the moon, or the force between Earth and the sun?
answer
Earth-sun
question
Jupiter has more than 300 times the mass of Earth. Yet on Jupiter's surface an object only about 3 times as much as it would on Earth. The explanation to this involves Jupiter's
answer
large radius
question
If you stood atop a ladder on Earth that was as tall as Earth's radius (so you were twice as far from Earth's center) your weight atop the ladder would be
answer
one-quarter its normal value
question
Since Earth is attracted to the sun, why doesn't it fall into the sun?
answer
Because it has sufficient tangential velocity.
question
A 560-N woman stands on top of a very tall ladder so she is one Earth radius above Earth's surface. How much does she weigh?
answer
140 N
question
Suppose the gravitational force between two masses is 70 N. If the magnitude of one of the masses halves, what is the force between the masses?
answer
35 N
question
Suppose the gravitational force between two spheres is 70 N. If the distance between the spheres is halved, what is the force between the masses?
answer
280 N
question
Suppose the gravitational force between two spheres is 30 N. If the magnitude of each mass doubles, what is the force between the masses?
answer
120 N
question
Compared to the gravitational field on the surface of the Earth, the gravitational field well below the Earths surface is
answer
smaller
question
The gravitational field strength at the center of the Earth is
answer
zero
question
If you drop a stone into a hole drilled all the way to the other side of Earth, the stone will
answer
speed up until it gets the center of Earth
question
If you were to weigh yourself in an elevator that is accelerating upward, compared to your ordinary weight you would weigh
answer
more
question
If you were to weigh yourself in an elevator that is in free fall, compared to your ordinary weight, you would weigh
answer
zero
question
There are two main processes going on in the sun that keep the sun in existence. These processes are gravitation and
answer
nuclear fusion
question
If the sun were to collapse to form a black hole (quite unlikely), Earth would
answer
orbit the black hole just as it orbits the sun now
question
When a star collapses to form a black hole, its mass
answer
remains the same
question
If a weight scale shows that you weigh 200 kg on the surface of Earth, and then you skydive with both of your feet attached to the scale, you will read a weight of
answer
0 kg
question
If you stand on a weight scale in an elevator that is accelerating upwards, why do you observe an increase in your weight?
answer
Because you are accelerating upwards, there is more compression of the springs of the scale. The weight reading on the scale reflects the amount of compression of the springs.
question
One way that astronauts detect planets around distant stars is by observing to see if there is a _________ in the light that reaches us from a particular star. The reason that the star moves away or toward us is a __________ due to gravitational effects of the planet.
answer
Doppler shift, perturbation
question
The distance to the center of the Earth is
answer
4000 miles
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New