Spring Interim / Midterm

One key difference between the way that Newton's Law of Universal Gravitation says gravity behaves and the way Coulomb's Law says the electric force behaves is ---.

• there are two types of electric charge that can neutralize each other, but only one type of mass

• the electric force depends on the distance between charges but the gravity force does not depend on the distance between masses

• gravity can both attract and repel, but electric force can only attract

• gravitational force can act over long distances, but electric force only acts over short (subatomic) distances

Which is stronger, the electric force between two charges or the gravitational force between the same two charges?

• the gravitational force is 39 times stronger than the electric force

• the electric force is 39 times stronger than the gravitational force

• the gravitational force is 10³⁹ times stronger than the electric force

• the electric force is 10³⁹ times stronger than the gravitational force

The statement "This force follows an inverse-square law, so that the force is inversely dependent on the square of the distance between two objects" describes ---.

• only the electrostatic force

• only the gravitational force

• both the electrostatic and gravitational force

• neither the gravitational nor the electrostatic force

Which of the following statements is true about both the gravitational force and the electrostatic force?

• The force can attract for opposite types of (mass or charge), and repel for like types.

• The force is inverseley related to the square of the distance.

• The force only shows up when objects are in contact, i.e. touching.

• The gravitational force and electrostatic are about equally strong.

What happens to the force between two charged objects if you double the distance between them and double the magnitude of one charge?

• 4X
• 6X
• 1/2X
• 1/6X

If the distance between two electrically-charged objects doubles, what happens to the electrostatic force?

• becomes 1/2 what it was

• becomes 1/4 what it was

• stays the same

• becomes 4× what it was

The graph shows the relationship between the force of interaction and the magnitude of charge. What type of relationship is this?

• Direct

• Indirect

• Inverse

• Reverse

An object that started out neutral becomes positively charged. This means that it ___ some ___.

• gained --- protons

• lost --- protons

• gained --- electrons

• lost --- electrons

Which of these is the best definition of polarization?

• The object gains a positive or negative charge from another object.
• The charges in a neutral object separate due to a nearby charged object.
• Charges on a neutral object jump off onto a charged object due to attraction of opposite charges.
• Two objects attract each other because they are both charged.

A negatively charged rod is touched to the top of an electroscope. Which shows the resulting charge?

• A

• B

• C

• D

• E