Magnetism Basics
What is magnetism?
This force can push or pull objects without direct contact.
What is gravity?
This force pulls objects toward Earth.
Two forces of 50 N and 50 N act in opposite directions. The net force is this
0 newtons
What law explains why objects at rest stay at rest unless acted on by a force?
1st law
If a river current increases against a boat’s direction of travel, the boat will do this.
slow down
When the north pole of one magnet is near the south pole of another, what will the magnets do?
attract
What is friction?
This force that acts in an opposing direction to an object in motion.
If one person pushes a box with 120 N and another pushes in the same direction with 80 N, this is the net force.
200 newtons
Which law explains how force, mass, and acceleration are related?
2nd law
Acceleration depends on force and this property of an object
mass
What will happen to two magnets when both their north or south poles are facing each other
They repel
What kind of force is this: When a swimmer pushes water backward to move forward
applied
A dog pulls forward with 90 N while the owner pulls back with 100 N. The net force is this direction and size.
10 newtons backward
When you push on the ground while running, the ground pushes back with an equal force because of what law?
Newtons 3rd law
A 1-kg ball accelerating at 2 m/s² has this net force
2N
A magnet attracts a paper clip but does not attract a plastic bead placed right next to it. This happens because magnetic force only acts on objects made of what type of material?
iron or steel
What kind of force is this: This upward force from a surface supports objects against gravity?
Normal force
Balanced forces result in what type of motion?
No change in motion (constant speed or rest)
In Newton’s Third Law, forces always come in these.
action–reaction pairs
When the net force acting on an object is zero, the object will do what?
stay at rest or move at a constant speed
What changes impact the magnetic force?
Changing the distance, strength, or orientation of magnets
Water pushing against a swimmer as they move is an example of what force?
Friction: water resistance (or drag)
Unbalanced forces always cause this...
Motion/acceleration
According to Newton’s Third Law, the forces are equal in size but opposite in...
Direction
As the distance between Earth and the Moon increases, what force between them becomes weaker?
gravitational force