Why don't forces cancel each other out when they act on two different bodies?

In summary, when forces act on two different bodies with the same magnitude and opposite directions, they do not cancel each other out because they are acting on separate objects. This is similar to the example of two people hitting two balls on a billiard table, where the forces do not cancel each other out and the balls move in opposite directions. This is a common question and may have a corresponding FAQ.
  • #1
manimaran1605
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Why forces acts on two different bodies with same magnitude and opposite in direction doesn't cancel each other?
 
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  • #2
manimaran1605 said:
Why forces acts on two different bodies with same magnitude and opposite in direction doesn't cancel each other?
Because each force acts on a different body. If two equal and opposite forces act on the same body, then they do cancel.
 
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  • #3
Doc Al said:
Because each force acts on a different body. If two equal and opposite forces act on the same body, then they do cancel.

This question is being asked very frequently. Is there any FAQ for this?
 
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  • #4
Let me give you an example. You and your friend are standing at opposite sides of a billiard table facing each other. Then you hit two balls simultaneously with equal and opposite forces. Do you expect that the two balls don't move?
 
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According to Newton's Third Law, for every action there is an equal and opposite reaction. This means that when two bodies interact, they exert equal and opposite forces on each other. However, these two forces do not cancel each other out because they act on different bodies.

To understand this, we must first define what a force is. A force is a push or pull that acts on an object and causes it to accelerate. When two bodies interact, they exert forces on each other in opposite directions. These forces act on different bodies, and therefore, they do not cancel out.

For example, if you push against a wall, the wall exerts an equal and opposite force on you. However, these two forces act on different bodies - you and the wall - and therefore, they do not cancel out. The force you exert on the wall causes it to remain stationary, while the force from the wall on you causes you to feel the resistance of the wall.

In another example, when a person jumps off a diving board, they exert a downward force on the board, while the board exerts an equal and opposite upward force on the person. These two forces act on different bodies and do not cancel out. The downward force from the person causes the board to bend, while the upward force from the board propels the person into the air.

In summary, forces act on different bodies and do not cancel out because they cause different objects to accelerate in different directions. Newton's Third Law explains that these forces are equal and opposite, but they do not cancel out as they act on different bodies.
 

What is Newton's Third Law?

Newton's Third Law states that for every action, there is an equal and opposite reaction. This means that when one object exerts a force on another object, the second object will exert an equal and opposite force back on the first object.

How does Newton's Third Law relate to forces?

Newton's Third Law explains how forces act in pairs. When an object exerts a force on another object, it is also experiencing an equal and opposite force in the opposite direction. This is why forces always occur in pairs.

Can Newton's Third Law be applied to all forces?

Yes, Newton's Third Law is a fundamental principle of physics and applies to all forces, whether they are contact forces (such as pushing, pulling, or friction) or non-contact forces (such as gravity or electromagnetic forces).

How does Newton's Third Law affect the motion of objects?

Newton's Third Law plays a crucial role in determining the motion of objects. When two objects interact, the forces they exert on each other will cause them to accelerate in opposite directions. This means that the objects will move in equal but opposite directions, resulting in a change in their velocity.

What are some real-life examples of Newton's Third Law in action?

Some common examples of Newton's Third Law include a person pushing a shopping cart (the person exerts a force on the cart, and the cart exerts an equal and opposite force back on the person), a rocket launching (the rocket's engines exert a force on the ground, and the ground exerts an equal and opposite force back on the rocket), and a person diving off a diving board (the person exerts a force on the board, and the board exerts an equal and opposite force back on the person).

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