Select the two variables that affect the strength of gravity between objects.

Question

options:

Mass
Mass

Shape
Shape

Density
Density

Velocity
Velocity

Distance
Distance

Magnetism

Answer 1

The two variables that affect the strength of gravity between objects are:

1. Mass - The gravitational force between two objects is directly proportional to the product of their masses.

2. Distance - The gravitational force is inversely proportional to the square of the distance between the centers of the two objects.

So the correct selections are Mass and Distance.

Answer 2

A teacher holds two negatively charged balloons near each other. She says that there is a force between the balloons. How will the balloons behave that will support the teacher’s claim?

options:

The balloons will not move.
The balloons will not move.

The balloons will become neutral.
The balloons will become neutral.

The balloons will move away from each other.
The balloons will move away from each other.

The balloons will move towards each other.

Answer 3

The correct option that supports the teacher's claim is:

The balloons will move away from each other.

Since both balloons are negatively charged, they will repel each other due to the like charges. Therefore, they will move away from each other, demonstrating the force between them.

Answer 4

Zack places iron filings on a piece of paper near a bar magnet. The iron filings quickly move and form a pattern around the magnet. Which argument does this evidence BEST support?

options:

Magnetic fields exist between objects that are not directly touching each other.
Magnetic fields exist between objects that are not directly touching each other.

Big magnets can attract more objects.
Big magnets can attract more objects.

Only materials that are made of metal have a magnetic force.
Only materials that are made of metal have a magnetic force.

A magnet can attract all objects through different materials.

Answer 5

The best argument that the evidence with iron filings supports is:

Magnetic fields exist between objects that are not directly touching each other.

The behavior of the iron filings arranging themselves in a pattern around the magnet demonstrates the presence of a magnetic field, which exerts a force on the filings even though they are not in direct contact with the magnet.

Answer 6

Ellie made an electromagnet with wire, a nail, and a 2.5-volt battery. The electromagnet attracted a paper clip from 2 inches away.

What action will make the electromagnet weaker?

options:

She can use a thicker piece of wire.
She can use a thicker piece of wire.

She can use a higher voltage battery.
She can use a higher voltage battery.

She can wrap the wire more times around the nail.
She can wrap the wire more times around the nail.

She can decrease the number of coils around the nail.
She can decrease the number of coils around the nail.

Answer 7

The action that will make the electromagnet weaker is:

She can decrease the number of coils around the nail.

Reducing the number of coils will decrease the strength of the magnetic field generated by the electromagnet, making it weaker.

Answer 8

Electric motors create motion by using magnets and electromagnets.

What can a person do to make an electric motor stronger?

options:

Add coils to the electromagnet and use larger magnets
Add coils to the electromagnet and use larger magnets

Add coils to the electromagnet and smaller magnets
Add coils to the electromagnet and smaller magnets

Remove coils from the electromagnet and use larger magnets
Remove coils from the electromagnet and use larger magnets

Remove coils from the electromagnet and use smaller magnets

Answer 9

The best choice to make an electric motor stronger is:

Add coils to the electromagnet and use larger magnets.

Increasing the number of coils enhances the strength of the electromagnet, and using larger magnets increases the magnetic field strength, both of which contribute to a stronger overall motor.

Answer 10

A girl is trying to make a simple electromagnet to help her pick up a piece of metal she dropped under a car. Which list of materials would she need to make an electromagnet?

options:

wooden rod for a core, copper wire, 12-volt battery
wooden rod for a core, copper wire, 12-volt battery

glass rod for a core, copper wire, 12-volt battery
glass rod for a core, copper wire, 12-volt battery

plastic rod for a core, copper wire, 12-volt battery
plastic rod for a core, copper wire, 12-volt battery

metal rod for a core, copper wire, 12-volt battery

Answer 11

The correct list of materials she would need to make a simple electromagnet is:

metal rod for a core, copper wire, 12-volt battery.

A metal rod (such as an iron nail) is essential for creating a strong electromagnet, as it enhances the magnetic field produced by the current flowing through the copper wire.