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# confused:is reaction force aka contact force the force explained by Newton's 3rd law?

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1. Whilst doing statics in m2 I have seen that the reaction force acts perpendicular to the surface , always. This is true even if the force acting is not perpendicular to the surface . But according to Newton's third law direction for reaction should be equal and act in the opposite direction to the incoming Force. Can someone please explain what is going on?
2. (Original post by thebrahmabull)
Whilst doing statics in m2 I have seen that the reaction force acts perpendicular to the surface , always. This is true even if the force acting is not perpendicular to the surface . But according to Newton's third law direction for reaction should be equal and act in the opposite direction to the incoming Force. Can someone please explain what is going on?
Reaction force is NOT always perpendicular to the surface. This is only the case if there is no frictional, or equivalent, component.

The reaction force will have a component perpendicular to the surface, and may have a component parallel to the surface.

Can you provide an example where you think the reaction is perpendicular, but the acting force is not?
3. (Original post by Argylesocksrox)
The reaction force on an object Isn't newton's 3rd law.

Reaction forces are a display of Newtons 1st law.
I suggest checking that again.
4. (Original post by ghostwalker)
Reaction force is NOT always perpendicular to the surface. This is only the case if there is no frictional, or equivalent, component.

The reaction force will have a component perpendicular to the surface, and may have a component parallel to the surface.

Can you provide an example where you think the reaction is perpendicular, but the acting force is not?
After reconsidering some of the problems I realized the incoming forces are vertical and not at an angle to the surface like I previously thought. Thanks a lot.

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