Universal Gravitational Force

Two asteroids exert a gravitational force F, on each other. Sometime later, the asteroids are now three times as far from each other as before. Which of the following represents the gravitational force at this distance?

• $\frac{F}{3}$

• $\frac{F}{2}$

• $\frac{F}{6}$

• $\frac{F}{9}$

An object has a mass of 50 kg and a weight of 500 N when it is resting on the surface of the Earth. If it is moved to a height equal to three times the Earth’s radius, what is the object’s new weight?

• $300\ N$

• $30\ N$

• $130\ N$

• $60\ N$

The moon's distance from the center of the Earth was decreased by a multiple of three. How would this affect the gravitational force of the Earth on the moon?

• It would increase by a factor of nine.

• It would decrease by a factor of nine.

• It would increase by a factor of three.

• The gravitational force would not be affected, because the moon's mass is the same.

A body with mass m is situated 3.0 meters from a second body with a mass of 2 m. What will be the effect on gravitational attraction of moving one body so that it is only 1.74 meters from the other body?

• It will increase by a factor of 3

• It will increase by a factor of 1.74

• It will decrease by a factor of 1.74

• It will decrease by a factor of 3

• It will increase by a factor of 9

Which of the following changes would increase a satellite's orbital speed?

• Decrease the mass of the satellite

• Decrease orbital radius

• Increase orbital radius

• Increase the mass of the satellite

• Decrease the mass of the Earth

2 lead spheres having mass of 1000 kg each are placed with their centers 1 m apart. gravitational force with which they attract to each other will be ....

• $6.673\times10^5\ N$

• $66.73\times10^5\ N$

• $6.673\times10^{-5}\ N$

• $66.73\times10^{-5}\ N$

The mass of the body on moon is 40 kg, what is the weight on the earth.

• 240 N

• 392 N

• 340 N

• 400 N

The distance between two bodies becomes 6 times more than the usual distance. The F becomes ...

• 36 times

• 6 times

• 12 times

• 1/36 times

Each of five satellites makes a circular orbit about an object that is much more massive than any of the satellites. The mass and orbital radius of each satellite are given below. Which satellite has the greatest speed?

• A

• B

• C

• D

• E

A person weighing 800 newtons on Earth travels to another planet with twice the mass and twice the radius of Earth. The person's weight on this other planet is most nearly……

• $400\ N$

• $\frac{800}{\sqrt{2}}\ N$

• $800\ N$

• $800\sqrt{2}\ N$