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# Newtons 3rd law Watch

1. So i understand the concept of Newtons thrid law: Every object has an equal and opposite force so for example if i was to push a door if its pushing with an equal and opposite force in the opposite direction to me, the how is it i can open the door? as it is pushing equal and opposite so surely it will create an overall force of 0 as they will cancel each other out..

Always found it hard from the concept of newtons 3rd law to work out how its possible
2. (Original post by hazbaz)
So i understand the concept of Newtons thrid law: Every object has an equal and opposite force so for example if i was to push a door if its pushing with an equal and opposite force in the opposite direction to me, the how is it i can open the door? as it is pushing equal and opposite so surely it will create an overall force of 0 as they will cancel each other out..

Always found it hard from the concept of newtons 3rd law to work out how its possible
Well if you manage to push it open, then obviously you're force is greater than the door's.

P.S That is not correct.

Newton's Third Law: For every action, there is an equal and opposite reaction.
Well if you manage to push it open, then obviously you're force is greater than the door's.

P.S That is not correct.

Newton's Third Law: For every action, there is an equal and opposite reaction.
Well ye but surley then that jut condradicts the law,as there it isnt an equal force
4. you have to thing of the pushing force as being broken down into two forces. one part is pushing on the surface of the door, the other part pushes on the door as a whole. the door pushes back equally and oppositely on the surface of your hand to stop the hand actually moving through door, but does not push back on you as a whole because the door has no acceleration. (Newton's second law).

Hope this helps!!
5. (Original post by drury-c4)
you have to thing of the pushing force as being broken down into two forces. one part is pushing on the surface of the door, the other part pushes on the door as a whole. the door pushes back equally and oppositely on the surface of your hand to stop the hand actually moving through door, but does not push back on you as a whole because the door has no acceleration. (Newton's second law).

Hope this helps!!
Ahaha it all becomes clear thanks that has bugged me for soo long lol
6. (Original post by drury-c4)
you have to thing of the pushing force as being broken down into two forces. one part is pushing on the surface of the door, the other part pushes on the door as a whole. the door pushes back equally and oppositely on the surface of your hand to stop the hand actually moving through door, but does not push back on you as a whole because the door has no acceleration. (Newton's second law).

Hope this helps!!
Uh, no.

The point is that they act on different objects. Yes there is an equal and opposite reaction, but it acts on you, not the door. The only force acting on the door is you pushing it, hence it moves.
7. the door does push back with an equal and opposite force. compare the weight of the door to you, obviously it'll be more effected by the push.

try push a door that's your own weight it would be a different story
8. (Original post by the maths guy)
the door does push back with an equal and opposite force. compare the weight of the door to you, obviously it'll be more effected by the push.

try push a door that's your own weight it would be a different story
You haven't answered the OP's question. And you could still open a door that was your own weight.
9. newton's third law.....a force exerted experiance an equal, opposite force. this rule applies when tht particular component is in equilibrium, hence a=0.
10. (Original post by Rahul.S)
newton's third law.....a force exerted experiance an equal, opposite force. this rule applies when tht particular component is in equilibrium, hence a=0.
No, it's a universal law. Can people stop posting crap in this thread please.
11. (Original post by TableChair)
No, it's a universal law. Can people stop posting crap in this thread please.
WTF...my statement corroborates with the law. im jus plainly explaining newton's law and terms. clearly u need to understand law properly.

wen i smash the table on ur head, then crush the chair through u....it will be to late for u to get it!

RIP TableChair <<<<universal law
12. (Original post by Rahul.S)
WTF...my statement corroborates with the law. im jus plainly explaining newton's law and terms. clearly u need to understand law properly.

wen i smash the table on ur head, then crush the chair through u....it will be to late for u to get it!

RIP TableChair <<<<universal law
'this rule applies when tht particular component is in equilibrium, hence a=0.'

Not only do I have no clue what you are on about since newtons 3rd law is always applicable, you clearly haven't answered the OP's question.

13. (Original post by TableChair)
'this rule applies when tht particular component is in equilibrium, hence a=0.'

Not only do I have no clue what you are on about since newtons 3rd law is always applicable, you clearly haven't answered the OP's question.

ffs! f=ma using tht knowledge u can prove newton's third law. 3rd law is only applicable wen a=0. a represents acceleration u noob, hence object will be in equilibrium or dynamic equilibrium. others will understand this, those who actually know mechanics and physics unlike u!

RIP TableChair<<<<FACT!
14. (Original post by Rahul.S)
ffs! f=ma using tht knowledge u can prove newton's third law. 3rd law is only applicable wen a=0. a represents acceleration u noob, hence object will be in equilibrium or dynamic equilibrium. others will understand this, those actually know mechanics and physics unlike u!

RIP TableChair<<<<FACT!
The third law is always applicable, it is not only applicable when a = 0.
15. This is because the forces are acting on seperate objects, forces only cancel each other out if they are acting on the SAME object, so if I push a door, I'm applying a force on the door, that is the ONLY force on the door, there are no other external forces acting on the door to cancel out the force I am applying. Newtons first law shows that an object remains stationary or at constant velocity only if the net force ON the object is zero, this net force is the sum of the external forces ON the object. In this case the only force on the object is the force im exherting on it so the net force is not zero.

Hope this helped

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