How can objects move if every action has an equal and opposite reaction?

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In summary, the concept of equal and opposite reactions is a fundamental principle in Newton's third law of motion where for every action, there is an equal and opposite reaction. This law applies to everyday situations such as pushing a shopping cart or kicking a ball. These reactions cannot cancel each other out as they act on different objects. The reaction force is always equal to the action force and this law plays a crucial role in the law of conservation of momentum.
  • #1
MrPickle
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This law is confusing me. If everything needs an equal and opposite reaction how do things move? Surely everything should be stationary if this law is true?
 
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The forces act on different objects. For example, consider a ball dropped from a building. Ignoring drag, there is only 1 force acting upon it, which is the pull of gravity from the Earth acting on the ball. The other force that makes this an equal and opposite reaction is the ball pulling on the Earth. The forces are acting on different objects, therefore both objects move.
 
  • #3
Oh, I see! Thank you :)
 

1. What is the concept of equal and opposite reactions?

The concept of equal and opposite reactions is a fundamental principle in Newton's third law of motion. It states that for every action, there is an equal and opposite reaction. This means that when an object exerts a force on another object, the second object will exert an equal force in the opposite direction.

2. How does this law apply to everyday situations?

This law applies to everyday situations in many ways. For example, when you push a shopping cart, the cart exerts an equal and opposite force on you, pushing you in the opposite direction. Similarly, when you kick a ball, the ball exerts an equal and opposite force on your foot, propelling the ball forward.

3. Can equal and opposite reactions cancel each other out?

No, equal and opposite reactions cannot cancel each other out. While they may be equal in magnitude, they act on different objects and in opposite directions, so they do not negate each other. This is because forces always act in pairs and cannot act on the same object.

4. Is the reaction force always the same as the action force?

Yes, the reaction force is always the same as the action force. This is because they are equal and opposite forces that act on different objects. If the reaction force is not the same as the action force, then the objects would experience a net force and would accelerate in a particular direction.

5. How does this law relate to momentum?

Equal and opposite reactions play a crucial role in the law of conservation of momentum. This law states that in a closed system, the total momentum remains constant. When one object exerts a force on another, the first object loses some momentum while the second object gains an equal amount of momentum in the opposite direction, resulting in no change in the total momentum of the system.

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