Fields and Interactions Unit Assessment

Which of the following phenomena can’t be explained by a field?

• the Moon orbits around Earth.

• leaves change color during the fall.

• lightning strikes during a storm.

• a floating iron staple points north.

Which of these statements is incorrect?

• fields can affect objects at a distance.

• fields extend through space.

• fields store energy.

• fields are the same thing as forces.

Earth’s gravitational field_______________

• is about the same strength everywhere on earth’s surface.

• is the same strength everywhere in the universe.

• has zero strength beyond earth’s atmosphere.

• constantly changes due to earth’s rotation.

The gravitational force between two objects_______________

• only exists when at least one of the objects is really massive.

• is almost always attractive.

• is stronger the more massive one or both of the objects are.

• only affects the object with smaller mass.

Which of the following will decrease the electrostatic force between two negatively charged balloons?

• removing negative charges from one of the balloons

• adding additional negative charge to only one of the balloons

• moving the balloons closer together

• changing the orientations of the balloons while keeping the distance between them constant

If you increase the distance between two magnets, the force between them_______________

• eventually disappears.

• stays the same.

• increases.

• decreases.

Which is NOT a characteristic of gravity?

• gravity can be described by a field.

• everything with mass has gravity.

• gravity can be both attractive and repulsive.

• gravitational force decreases with distance.

Electric charges______________

• are dependent on mass.

• are small particles in atoms.

• always attract each other.

• are attracted to magnetic poles.

Two oppositely charged blocks are placed next to each other on an insulated table. They are not touching but cannot move. A small negatively charged object is placed between them. What happens to the small object?

• it moves toward the negatively charged block.

• it does not move.

• it moves toward the positively charged block.

• it moves upward away from both of the blocks.

Which of the following is NOT a characteristic of magnets?

• they can apply a force at a distance.

• they are always attractive.

• they affect all magnetic materials.

• they are surrounded by a magnetic field.