Physics Gravity Test

If an apple were placed in orbit at the same distance from earth as the moon, what acceleration would the apple have?

The same as the moon's

Why don't two pucks on an air hockey table accelerate toward each other due to their mutual gravitational attraction?

The traction is too small

The earth exerts a gravitational force of 7000 N on a satellite. What force does the satellite exert on the earth?

7000 N

And the law of universal gravitation the force _________ as the mass increases and ___________ as the distance increases.

A) increases B) decreases

Approximately what trajectory would you expect if we launched an apple with a speed of 10 km/s?

At 8 km/s it will follow a perfectly circular path but at 10 km/s it will follow an elliptical path

If a satellite in a circular orbit above the earth is continually "falling,"why doesn't it quickly return to earth?

Because it is falling similar to the curvature of the earth

Some of NASA's earth satellites remain above a single location on earth. Why don't these geosynchronous satellites fall to earth under the influence of gravity?

Because it is orbiting the earth

According to the law of universal gravitation, the gravitational influence of the earth gets weaker with distance. How far does it extend?

Forever

What force causes the planets to execute (nearly) circular orbits?

Gravity

Is the size of the gravitational force the earth exerts on the moon smaller then, larger than, or the same size as the force the moon exerts on the earth?

It is the same

Skylab caused quite a motion when you return to earth in July 1979. Why would it suddenly return to earth after it had been in orbit for many years?

It lost acceleration and earths gravity pulled it in

What happens to the surface area of a cube when the length of each side is doubled?

It quadruples

If we are able to launch an apple horizontally with a speed of 40 m/s, what path will it follow?

It will follow a parabolic path; no ordinary projectile motion

What do you think would happen to the moon's orbit if the gravitational attraction between the moon and the earth were slowly growing weaker?

It would increase in radius

Why don't two people feel the gravitational attraction between them?

It's too small to be noticed

Would you weigh more in New York City or in Denver? Why?

New York City because it's closer to the earth's center

A person find off a cliff feels weightless. Is the gravitational force on the person zero?

No, it is still mg.

And astronaut in the space shuttle feels weightless. Is the gravitational force on the astronaut zero?

No, the station and the astronaut are falling at the same rate

How can we determine the mass of a planet such as Venus, which has no moon?

Send a satellite to orbit it

Draw a picture of the moons orbit as viewed from a point far above the north pole the sun.

Squiggle line

Please comment on the following statement made by TV newscaster during an Apollo flight to the moon: "The spacecraft has now left the gravitational force of the earth."

That is impossible because the gravitational force of the earth never ends; it gets infinitely smaller

What do you expect the value of G to be larger or smaller than normal over a large deposit of uranium ore?

The gravitational force will be larger because of the higher density

The sun exerts a gravitational force on the moon. Does the moon orbit the sun?

Yes, the moon orbits the sun while orbiting the earth

If the earth had half its present mass and half its present radius, would your weight be different?

Yes, you would be two times as heavy

Would you weight more in a boat or on shore? Why?

You would weigh more on shore because the land is more dense than the water