Types of Forces
This force pulls objects toward Earth's center.
Gravity
Two students push a box to the right with 5 N each. What is the net force?
10 N right?
Two equal forces act in opposite directions. Are the forces balanced or unbalanced?
What are balanced forces?
Newton's Third Law states that every action force has an equal and opposite ______ force.
What is a reaction?
A magnet picks up a paper clip without touching it. What force is responsible?
What is magnetism?
This force opposes motion when two surfaces rub together.
Friction
One person pushes right with 15 N while another pushes left with 5 N. What is the net force?
What is 10 N right?
An object has a net force of 12 N to the left. Are the forces balanced or unbalanced?
What are unbalanced forces?
When you push against a wall, the wall pushes back on you with an equal and opposite force. What law explains this?
What is Newton's Third Law?
A parachute slows a falling skydiver because of this force from the air.
What is friction (air resistance)?
This force can attract or repel certain metals without touching them.
Magentism
Two equal forces push in opposite directions: 20 N right and 20 N left. What is the net force?
0 N?
A soccer ball is sitting still on the ground. Gravity pulls down while the ground pushes up equally. What is the net force?
What is 0 N?
A swimmer pushes water backward. What happens to the swimmer?
The water pushes the swimmer forward.
A car has 100 N of forward force and 70 N of backward force. What is the net force?
What is 30 N forward?
A book rests on a table. The table pushes upward on the book. What force is this?
Normal Force
A box experiences 35 N upward and 15 N downward. What is the net force?
20 N upward
A moving skateboard has balanced forces acting on it. Will it change its motion because of those forces?
What is no, its motion will not change?
A rocket pushes gases downward. In what direction do the gases push the rocket?
What is upward?
Two students pull a rope in opposite directions with 50 N each. What is the net force, and are the forces balanced?
What is 0 N, and the forces are balanced?
A student pushes a shopping cart forward. What type of force is the student applying?
What is an applied force?
Three forces act on a cart: 25 N right, 10 N left, and 5 N left. Calculate the net force and direction.
What is 10 N right?
A box has 40 N pushing right and 40 N pushing left. A student adds another 10 N pushing right. What is the new net force?
What is 10 N right, making the forces unbalanced?
A student pushes on a desk with 30 N of force. How much force does the desk exert on the student, and in what direction?
What is 30 N in the opposite direction?
A skateboarder pushes backward against the ground with their foot and moves forward. Identify the action force, reaction force, and scientific law.
The action is the foot pushing backward on the ground. The reaction is the ground pushing forward on the foot. Newton's Third Law.