Gravity and Magnetism

Magnetism is a Force

Understanding the Push and Pull of Magnets

Classifying Forces

• Scientists classify forces to make them easier to study.

• The classifications of forces are:

  • Contact Forces

  • Non-contact Forces

• Contact forces involve one object touching another object.

• Non-contact forces do not require the objects to touch. They work across a long distance.

Multiple Choice

Forces are classified as:

• Permanent

  Temporary

• Helpful

  Harmful

• Contact

  Non-Contact

• True

  False

Dropdown

​

Select answer

forces are exerted by objects that are touching,

while ​

Select answer

forces are exerted across a distance.

Gravity is a Force

• Gravity is a non-contact force.

• Gravity pulls two objects towards each other.

• Gravity is affected by distance and mass.

• On Earth, gravity pulls all things towards Earth's center.

• We can measure gravity using Weight.

Multiple Choice

Objects that are ___ attract more strongly.

• Close Together

• Far Apart

Multiple Choice

As two objects move farther apart, Gravity's pull will ___.

• Increase

• Decrease

• Stay the Same

Multiple Choice

Objects that are ___ attract more strongly.

• High Mass

• Low Mass

Multiple Choice

As two objects get heavier, Gravity's pull will ___.

• Increase

• Decrease

• Stay the Same

Open Ended

"Gravity is affected by ___ and ___.

Gravity gets stronger when ___, but gravity gets weaker when ___."

Multiple Choice

On Earth, gravity pulls everything towards Earth's center because ___.

• Gravity can only ever pull down.

• The magnets from the core cause the gravity.

• Nothing on Earth has a bigger mass than Earth.

Multiple Choice

___ is a measure of mass X gravity.

• Volume

• Density

• Weight

Magnetism is a Force

• Magnetism is also a non-contact force.

• Magnetism can pull objects together. We say "attract."

• Magnetism can push objects apart. We say "repel."

• An object that exerts magnetic force is called a magnet.

• Only metal objects can be attracted or repelled by magnets.

Dropdown

Magnetism is a ​

Select answer

force,

so the objects ​

Select answer

touching.

Dropdown

​

Select answer

means to pull towards, while ​

Select answer

means to push apart.

Multiple Choice

An object that exerts a magnetic force is called a ___.

• Magnet

• Magneto

• Mag-lev

• Magical

Multiple Choice

Only ___ objects can be affected by magnets.

• Plastic

• Wooden

• Metal

Magnetism Changes

• Two factors affect Magnetism:

  • How close the objects are

  • The poles of the objects

• Objects that are closer together can pull more strongly than objects far apart.

• As objects get farther apart, magnetism's pull gets weaker.

Multiple Choice

Objects that are ___ attract more strongly.

• Close Together

• Far Apart

Multiple Choice

As two objects move farther apart, a magnet's pull will ___.

• Increase

• Decrease

• Stay the Same

Magnetism Changes

• Two factors affect Magnetism:

  • How close the objects are

  • The poles of the objects

• All magnets have a North Pole and a South Pole.

• Opposite poles attract.

• Matching poles repel.

Dropdown

​

Select answer

poles attract,

but ​

Select answer

poles repel.

Dropdown

Matching poles ​

Select answer

,

but Opposite poles ​

Select answer

.

Open Ended

Attract or Repel?

"I predict these magnets will ___ because ___."

Open Ended

Attract or Repel?

"I predict these magnets will ___ because ___."

Magnetic Fields

• The space around a magnet is called a "Magnetic Field."

• Objects inside the field can be affected by magnetism.

• The field is invisible, but we can see its effects when we spill iron filings near a magnet.

Multiple Choice

The space around the magnet is called the ___.

• Magnetic Court

• Magnetic Field

• Magnetic Playground

• Magnetic Patio

Multiple Choice

Objects are only affected by magnetism if they are ___ the magnetic field.

• Inside

• Outside

• Under

Earth's Magnetic Field

• The Earth has a magnetic field.

• The magnetic field is created by the movement of liquid metal in Earth's Outer Core.

• Like any magnet, the Earth has a North and South Pole.

• Which pole is North or South switches every couple hundred thousand years.

Multiple Choice

Earth's magnetic field is created by liquid metal in the ___.

• Crust

• Mantle

• Outer Core

• Inner Core

Multiple Choice

The magnetic ends of Earth are called ___.

• North Pole and South Pole

• East Pole and West Pole

• Attract Pole and Repel Pole

Multiple Choice

The location of Earth's North Pole ___.

• Has always been the same

• Changes every day

• Changes after several hundred thousand years

Using Earth's Magnetic Field

• Earth's magnetic field can be useful for navigation.

• To navigate is to figure out where to go.

• Humans use a compass to navigate on land or sea.

• The needle in the compass always points North.

• Birds that migrate in the winter use Earth's magnetic field to navigate to their nests.

Multiple Choice

To ___ is to figure out where to go.

• Directate

• Navigate

• Planerate

Multiple Choice

An Ancient Chinese invention that uses magnets to help humans navigate is ___.

• GPS

• A compass

• A map

Open Ended

"Earth has a magnetic field because ___.

Earth has a magnetic field so ___."