The force of gravity acting on you will increase if you

Front

Stand on a planet with a radius that is shrinking

Back

An object is placed exactly halfway between earth and the moon. The object will fall toward

Front

The earth

Back

Two objects move toward eachother because of gravitational attraction. As the objects get closer and closer, the force between them

Front

Increases

Back

Since the earth is attracted to the sun, why doesn't it fall into the sun?

Front

Because it has sufficient tangential velocity

Back

Where does a satellite in an elliptical orbit have the greatest KE?

Front

At the point closest to the planet

Back

The speed of a satellite in a circular orbit is

Front

Constant

Back

The gravitational force between two massive spheres

Front

Is always an attraction, depends on how massive they are, and depends inversely on the square of the distances between them

Back

The gravitational field strength at the center of the earth is

Front

Zero

Back

The reason that satellites orbit the earth at least 150 km above the surface is to

Front

Be above earth's atmosphere

Back

If you were to weigh yourself in an elevator that is in free fall, compared to your ordinary weight, you would weigh

Front

Zero

Back

The force of gravity on you is the greatest when you are standing

Front

Just below earth's surface

Back

The curvature of earth is such that for every 8000vm tangent to the surface, the surface drops about

Front

5 m

Back

If earth's mass decreased to one half its original mass, with no change in radius, then your weight would

Front

Decrease to one half of your original weight

Back

Each of us weighs a tiny bit less on the ground floor of a skyscraper than we do on the top floor. One reason is that

Front

The mass of the building attracts you upward slightly

Back

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 stop the ladder would be

Front

One quarter it's normal value

Back

Newton hypothesized that the moon

Front

The moon is a projectile which is falling around earth and has a tangental velocity that prevents it from falling into earth. It is also attracted to earth

Back

If the mass of the earth increased, with no change in radius, your weight woukd

Front

Increase also

Back

If you drop a stone into a hole drilled all the way to the other side of the earth, the stone will

Front

Speed up until it gets to the center of the earth

Back

A projectile is fired vertically from the surface of earth at 10 km/s. The projectile will

Front

Rise and then fall back to the earth's surface

Back

Which is greater, the gravitational force between earth and the moon, or the force between earth and the sun?

Front

Earth and the sun

Back

Why did Newton think there was a force acting on the moon?

Front

Because the moon moves in a curved path

Back

Jupiter has more than 300 times the mass of earth. Yet on Jupiter's surface an object weighs only about 3 times as much as it would on earth. The explanation to this involves Jupiter's

Front

Large radius

Back

Minimal orbital speed about earth is approximately 8 km/s. Minimal orbital speed about the moon would be

Front

Less than 8 km/s

Back

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

Front

Twice as much

Back

Gravitational forces are the weakest fources found in nature. Because of this

Front

Gravitational forces that are easily observed involve one or more large masses

Back

Compared to the period of a satellite in orbit close to earth, the period of a satellite in orbit far from earth is

Front

Longer

Back

A supplier wants to make a profit by buying metal by weight at one altitude and selling it at the same price per pound at another altitude. The supplier should

Front

Disregard altitude because it has a negligible effect

Back

A lunar month is about 28 days. If the moon were closer to the earth than it is now, the lunar month would be

Front

Less than 28 days

Back

The fastest moving planet in the solar system is

Front

The planet nearest the sun

Back

If you were to weigh yourself in an elevator that is accelerating upward, compared to your ordinary weight you would weigh

Front

More

Back

A very massive object A and a less massive object B move toward eachother under the influence of mutual gravitation. Which force, if either, is greater?

Front

Both forces are the same

Back

If the radius of the Earth decreased with no change in mass, your weight would

Front

Increase

Back

If you stand on a weight scale in an elevator that is accelerating upwards, why do you observe an increase in your weight?

Front

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

Back

The circular orbit of a satellite orbiting earth is characterized by a constant

Front

Speed, radius, and magnitude of acceleration

Back

Where does a satellite in a circular orbit have the greatest KE?

Front

Anywhere- the KE is constant

Back

Newton had the insight to see that the

Front

Force on the moon has the same nature as the force on an apple

Back

The force of gravity on you is greatest when you are standing

Front

On earth's surface

Back

As a satellite is moving in orbit around the earth, the sum of the KE and PE everywhere is

Front

Constant

Back

If a weight scale shows that you weigh 200 kg on the surface of the earth, and then you sky dive with both of your feet attached to the scale, you will read a weight of

Front

0 kg

Back

A vertically oriented rocket that maintains a continuous upward velocity of 8 km/s will

Front

Escape earth

Back

The reason the moon does not fall into the earth is that

Front

The moon has a sufficiently large orbital speed

Back

Compared to the gravitational field on the surface of the earth, the gravitational field well below earth's surface is

Front

Smaller

Back

A hollow spherical planet is inhabited by people who live inside it, where the gravitational field is zero. When a very massive space ship lands on the planet's surface, the gravitational field inside the planet is

Front

Nonzero and directed toward the space ship

Back

The higher a satellite

Front

Less it's speed is and the longer it's period is

Back

Which of the following describes how circular and elliptical satellite orbits vary?

Front

In a circular orbit, neither the distance to earth nor the speed of the satellite vary. In an elliptical orbit, both the distance to earth and the speed of the satellite vary

Back

Newton reasoned that the gravitational attraction between earth and the moon must be

Front

Reduced by distance

Back

Consider the gravitational force between earth and a meteor in outer space. If the meteor moves so it's distance from the earth's center doubles, the gravitational force on the meteor will be

Front

One quarter

Back

A period of a satellite is defined as

Front

The time for a satellite to make one complete revolution around earth

Back

What remains constant for a satellite in elliptical orbit

Front

It's total energy

Back

Section 2

(14 cards)

A circle is a special case of

Front

An ellipse

Back

When in orbit, a satellite such as the space shuttle is

Front

Simply a projectile

Back

Force is directly proportional to

Front

mass

Back

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

Front

It would orbit earth

Back

The speed of a satellite in an elliptical orbit is

Front

Not constant

Back

Larger mass equals

Front

Higher circular and escape velocity

Back

The orbital speed for a satellite orbiting very close to earth's surface is

Front

8000 m/s

Back

Force is inversely proportional to

Front

The radius squared

Back

The early bird communications satellite hovers over the same point on earth's equated indefinitely. This is because

Front

It's orbital period is 24 hours

Back

Pluto takes a longer time to travel around the sun than earth takes because Pluto

Front

Has farther to go and goes slower

Back

Bigger planet equals

Front

Bigger gravity

Back

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?

Front

About 28 days

Back

An object dropped from rest almost infinitely far from earth falls to earth because of earth's gravitational field, and strikes the surface with a speed of about