Newton's Third Law: Why Is There Motion?

In summary, the conversation discusses the relationship between Newton's third law and motion. It is explained that the third law does not prevent motion, as the equal and opposite forces mentioned in the law act on different bodies and do not cancel out. Additionally, it is noted that Newton's third law includes reaction forces that occur when an object is accelerated. The conversation also mentions that while there may not be motion of the center of mass, there is motion of the individual objects involved.
  • #1
lewis198
96
0
I was wondering, if Newton's third law is true why is there motion?
 
Science news on Phys.org
  • #2
lewis198 said:
I was wondering, if Newton's third law is true why is there motion?
Why do you think that Newton's 3rd law would prevent motion? Note that the equal and opposite forces mentioned in Newton's 3rd law act on different bodies, thus they don't cancel--if that's what you're thinking.
 
  • #3
According to the third law.if two blocks collide each other. they apply force on each other by equation F=-F.
note:when block hits another block. it moves when it collides with Inertia.
 
  • #4
Newton's third law includes reaction forces. When an object is accelerated, it reacts with an opposing force equal in magnitude to the force accelerating it.
 
  • #5
lewis198 said:
I was wondering, if Newton's third law is true why is there motion?

actually
It says there is no motion of their centre of mass.

But there IS motion of the the 2 individual objects. Obviously.
 

FAQ: Newton's Third Law: Why Is There Motion?

What is Newton's Third Law?

Newton's Third Law, also known as the Law of Action and Reaction, 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 explain motion?

Newton's Third Law explains motion by stating that in order for an object to move, there must be a force acting on it. This force can come from another object, such as a person pushing a cart, or from the object itself, such as a rocket propelling itself forward. The equal and opposite reaction forces between objects result in motion.

Can you give an example of Newton's Third Law in everyday life?

Yes, a common example is when you push a door open. As you exert a force on the door, the door exerts an equal and opposite force back on you. This allows the door to move and open. Another example is when you swim in a pool. As you push the water backwards with your arms and legs, the water pushes back on you, propelling you forward.

Does Newton's Third Law only apply to objects in motion?

No, Newton's Third Law applies to all objects, whether they are in motion or not. Even if an object is at rest, there are still forces acting on it that follow the principles of Newton's Third Law. For example, the force of gravity pulling an object down is countered by the force of the ground pushing up on the object.

Are there any exceptions to Newton's Third Law?

While Newton's Third Law holds true in most situations, there are some cases where it may not apply. For example, in some cases of friction, the forces may not be equal and opposite due to differences in surface materials. Additionally, in situations involving non-contact forces, such as magnetic or electrical forces, the equal and opposite reaction may not be as apparent.

Similar threads

Replies
28
Views
3K
Replies
9
Views
2K
Replies
7
Views
3K
Replies
6
Views
1K
Back
Top