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GCSE physics newton's third law

Hey guys,
can anyone explain this please as i am confused with how this law works with an object at equilibrium and how it works when objects do and don't move.
Thanks for any help :smile:
Reply 1
Avatar for Squirmz
Squirmz
17
So if a force acts on something, the same force acts back. Like if I punch someone, I get the same force acting on my fist as is acting on their (now deformed) face. If there is movement in both objects, then the force changes according to the relative velocity of the objects. But you won’t need to know it in that much detail. All you need to know is if you push it, it pushes back. And you will need to apply this to certain every-day things
Hiya,
in the specification it says this
Newton’s Third Law:
Whenever two objects interact, the forces they exert on each other are
equal and opposite.
Students should be able to apply Newton’s Third Law to examples of
equilibrium situations.

In the application in situations of equilibrium what does this mean? , is it just literally like the situation you explained above.
Sorry to ask again, many thanks :smile:
Original post by mazenod
So if a force acts on something, the same force acts back. Like if I punch someone, I get the same force acting on my fist as is acting on their (now deformed) face. If there is movement in both objects, then the force changes according to the relative velocity of the objects. But you won’t need to know it in that much detail. All you need to know is if you push it, it pushes back. And you will need to apply this to certain every-day things
Reply 3
Avatar for Squirmz
Squirmz
17
Equilibrium is where no forces act on an object and so it does not accelerate/decelerate. For GCSE, we were told only that we need to recognise it when seen, and perhaps explain what it means. What they mean by ‘equilibrium situations’ is basically saying that there won’t be any complications due to direction, angles, acceleration etc. So you can assume that one of the objects will be stationary
Ahh thanks a lot 😄
Original post by mazenod
Equilibrium is where no forces act on an object and so it does not accelerate/decelerate. For GCSE, we were told only that we need to recognise it when seen, and perhaps explain what it means. What they mean by ‘equilibrium situations’ is basically saying that there won’t be any complications due to direction, angles, acceleration etc. So you can assume that one of the objects will be stationary
Reply 5
Avatar for Squirmz
Squirmz
17
Original post by Fosbourne85
Ahh thanks a lot 😄


You’re welcome 😃
Reply 6
Avatar for Suley143
Suley143
7
Hi,

Think of a heavy object on your bedroom floor. Newtons third law states that when 2 objects interact the forces they exert on one another are equal and opposite. So let's examine this - the heavy object has gravitational force pushing down on the bedroom floor but it's not falling through your floor, so your floor must be pushing back up (this is called reaction force) with an equal and opposite force .. this keeps tha ball stationary on your bedroom floor because there is no resultant force - upward and downward forces are balanced (equilibrium). If there was a resultant force the object will either fall through the floor or shoot up into the air because the object will move (accelerate) in the direction of the unbalanced, resultant force.

Hope this helps.
(edited 4 years ago)

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