Physics Test 9

Which path could be made by launching a positively charged particle (red) past the fixed negatively charged particle (blue) shown in the diagram?

• Path A

• Path B

• Path C

• Path D

Which statement is true?

• Positively charged objects are attracted to other positively charged objects.

• Negatively charged objects are attracted to other negatively charged objects.

• Both A and B are true.

• D. None of the answers are true.

Which grid will result in the launched negatively charged particle moving upwards?

• Grid A

• Grid B

• Grid A and grid B

• Neither grid

Two charged objects near one another may experience acceleration either toward or away from each other because each object exerts a force on the other object (according to Newton’s 2^nd Law). This force is called

• the electric force

• the gravitational force

• the frictional force

• the unified force

The distance between two objects affects the magnitude of the electric force between them.

• True

• False

When the distance between two charges is cut in half, the force between them:

• increases by a factor of four.

• increases by a factor of two.

• decreases by a factor of four.

• decreases by a factor of two.

What is the electric force between two objects each having a charge of 0.25 Coulombs that are 2.0 meters apart? HINT: k_c = 9.0 x 10⁹ Nm²C².

• 2.8 x 10⁸ N

• 3.6 x 10⁹ N

• 1.7 x 10⁷ N

• 4.0 x 10⁸ N

Over time, all the negative charges in an object:

• remain clustered together where they were placed.

• spread out over a small area on the object.

• spread out over a large area on the object.

When a charged object touches a conductor (like a door knob):

• the positive charges move to the conductor and exit the object.

• the negative charges move to the conductor and exit the object.

• both the positive and negative charges move to the conductor and exit the object.

• neither the positive nor the negative charges move to the conductor and exit the object.

if an atom contains equal numbers of protons and electrons, the atom is described as being:

• electrically neutral.

• negatively-charged.

• positively-charged.

• anti-matter.