Forces Come in Pairs

What is the common characteristic of forces in an interaction?

What is the result of an interaction between objects?

Which of the following is an example of a non-contact interaction?

What is the relationship between the action and reaction forces in an interaction?

What is the first step in identifying the action and reaction forces between objects?

What is a common characteristic of the examples of pairs mentioned in the text?

What is an example of an interaction involving physical contact?

What is the primary characteristic of an action-reaction pair of forces?

What happens when two equal and opposite forces act on the same object?

What is the primary factor that determines the effect of an action-reaction force pair on an object?

What is the relationship between the force and acceleration of an object according to Newton's second law of motion?

Why does a cannon recoil less than a cannonball when fired?

What happens to the acceleration of an object when the force acting on it increases?

What is the relationship between the magnitude of the action and reaction forces?

What happens to the bug when it hits the windshield of a moving car?

Forces Come in Pairs

Forces always come in pairs, and when one force acts, there's an equal and opposite force acting against it.
Forces are the result of an interaction between objects, which can be physical contact or non-contact.

Newton's Third Law of Motion

States that for every action force, there's an opposed and equal reaction force.
When one object exerts a force on another, the second object exerts an equal magnitude and opposite-direction force back on the first.
The two forces are always equal in strength and opposite in direction.

Identifying Action and Reaction

To identify the action and reaction forces, identify the interaction between objects.
Examples of interactions: push-up on the floor, tennis racket hitting a tennis ball, and a rocket launching off the ground.
In each interaction, the action force is exerted by the first object on the second, and the reaction force is exerted on the first object by the second.

Different Objects

Action and reaction forces act on different objects in the interaction.
Two equal and opposite forces acting on the same object do not make an action-reaction pair.
This is why the two opposing forces don't cancel out.

The Effect of the Forces

The mass of the objects in the interaction determines the effect of the forces.
When the force increases, acceleration increases, but as the mass increases, acceleration decreases.
More mass means less acceleration.

Action Equals Reaction

Action always equals reaction, no matter how much force you try to exert on an object.
The force exerted on an object is the same force exerted on the other object in the interaction.
The effect on the objects depends on their mass.

Learn about the fundamental concept of forces and their interactions, including equal and opposite forces that act upon each other. Understand how forces arise from interactions between objects.