Gravity
What is the force that pulls objects toward Earth’s center called?
Gravity
What happens when two north poles of magnets are brought close together?
They repel.
What type of electricity is caused by a buildup of electrons on an object?
Static electricity.
Is a metal fork a conductor or an insulator?
Conductor.
Why does an astronaut weigh less on the Moon than on Earth?
The Moon has weaker gravity (about 1/6 of Earth’s).
Where is the magnetic force strongest on a magnet?
At the poles (the ends).
In a copper wire, what is actually moving to create electric current?
Electrons.
Is a rubber band a conductor or an insulator?
Insulator.
What two factors affect the strength of gravity between two objects?
Mass and distance.
What material makes the best core for an electromagnet: aluminum, copper, wood, or iron?
Iron.
What happens to the rest of the lights in a series circuit if one bulb burns out?
The whole circuit stops; all lights go out.
Why does a balloon stick to a wall after you rub it on your hair?
It becomes negatively charged and is attracted to the neutral wall.
Does your mass change on the Moon? Explain.
No—mass stays the same because it’s the amount of matter.
How can you increase the strength of an electromagnet? Name one way.
Add more wire wraps or increase the electric current.
Why does a switch turn a light off in a circuit?
It opens the circuit, breaking the path for electrons.
Two balloons repel each other after being rubbed with the same material. Why?
They have the same charge (like charges repel).
Explain how gravity keeps Earth in orbit around the Sun.
The Sun’s large mass pulls Earth toward it, curving its path into an orbit.
Explain why a magnet can separate iron from sand.
The magnet attracts iron particles but not sand.
In a parallel circuit, why do the other loads keep working even if one stops?
There are multiple paths, so electricity can still flow through the others.
Replacing a conductor with an insulator in a circuit affects the flow of electrons how?
The flow decreases or stops because electrons cannot move through an insulator.