How is motion possible if Newtons third law applies?

For every force there is an equal and opposite force



So if I push a door then the door pushes back but why is it that the door opens? Why is there motion if for every force there is an equal counter force?How is motion possible if Newtons third law applies?Newton's 3rd Law applies to equal and opposite forces on different objects. If i push on a wall it pushes back on me with equal force that i exert on it, but it is not a 3rd law equal and opposite force because there is no object between. The equal and opposite forces only CANCEL when they act on the same object, not each other.

Force 1 --%26gt; object %26lt;-- Force 2 (where F1 = F2)

You needing to pee -%26gt; bathroom door %26lt;- your friend being an ***

These forces cancel each other out because the equal and opposite forces are acting on the same object so it will not move.



Now imagine a rocket blasting into space.

The rocket burns the fuel and pushes the gas out and the gas pushes on the rocket with equal force. The rocket pushes the gas down towards the ground and the gas reacts by pushing the rocket skyward.



For forces to cancel they need to act on different objects.



Note that not all equal and opposite forces are 3rd law forces, but all 3rd Law forces are equal and opposite.How is motion possible if Newtons third law applies?Normally you are heavier than the door. Added to that friction that holds you in place on the ground allows you to push the door open. Watch a 3-year-old try to open a heavy door sometime.