Unit 3 Test: Fields – Forces at a Distance

If m decreases by 5/8 and r decreases by 3/4, what happens to the force? (1 pt)

• Force decreases by a factor of 25/64

• Force decreases by a factor of 3/4

• Force stays the same

• Force increases by a factor of 10/9

• Force increases by a factor of 64/25

If M decreases by 1/22 and r decreases by 1/9, what happens to the force? (1 pt)

• Force decreases by a factor of 1/198

• Force decreases by a factor of 9/22

• Force stays the same

• Force increases by a factor of 9/2

• Force decreases by a factor of 81/22

In a vacuum, if you drop a bowling ball and a feather at the SAME time, the objects’ mass and shape affects which hits the ground first.

• True

• False

Why are neutral objects attracted to charged objects?

• Neutral objects are actually charged objects, so opposites attract.

• Charged objects have more energy than neutral objects.

• Charged objects polarize neutral objects by separating the different charges in the neutral object.

• Magic

What happens after a negatively charged rod touches a METAL sphere? (Refer to the image below) (1 pt)

• The electrons will stay where they are and NOT move (as seen in the image).

• The electrons will evenly distribute themselves across the surface of the sphere.

• The electrons will gather (as a group) on the opposite side of the sphere (opposite of their current position in the image).

• The image is wrong; the electrons would never leave the charged rod in the first place.

What type of force is responsible for the balloon sticking to the wall after being rubbed on hair?

• Gravitational force

• Coulomb force

• Magnetic force

• Drag force

• Magic

In the diagram above, white boxes = conductors while gray boxes = insulators. In the above diagram, a negatively charged object touches a neutral object that consists of conductors and insulators. Which diagram below correctly represents what would happen to the neutral object? (1 pt)

• 
• 
• 
• 

Why are the prongs on a charger block typically made of metal?

• The prongs are insulators, which allows them to conduct electricity efficiently.

• The prongs are magnetic, which allows them to conduct electricity efficiently.

• The prongs are conductors, which allows them to conduct electricity efficiently.

• The prongs are purely decorative and serve no functional purpose.

Harper and Noah are playing with a bar magnet. If they accidentally break the magnet in half, the result is that... (1 pt)

• The magnet loses its polarity.

• The magnet becomes two monopoles.

• The magnet explodes.

• The magnet becomes two magnets.

Emma is sorting through a box of various metal objects. She wonders if all the metals in the box are magnetic.

• True

• False