Static friction being the force that opposes the reaction

[TheWonderer1]

Hi there,

I was thinking that static friction works in opposition to a reaction force like the force of a fridge against you as you push it. However, since you are pushing horizontally and friction works against you why is it equal or greater than the reaction force? Will the force get negated by your body? I'm just trying to see the relation.

 

[Doc Al]

I was thinking that static friction works in opposition to a reaction force like the force of a fridge against you as you push it.

Not sure what you mean by "reaction force". You push the fridge and it pushes back with equal and opposite force; those are third law pairs. Friction acts between the fridge and the floor; they exert equal and opposite forces on each other.

However, since you are pushing horizontally and friction works against you why is it equal or greater than the reaction force?

As long as the force you exert on fridge is less than or equal to the maximum static friction force that the floor can exert on the fridge, those forces will be equal and opposite. But they are not "action/reaction" pairs.

 

[TheWonderer1]

Blah sorry meant someone explained it to me like the above statement. My question is mainly what is force acting against you that prevents you from flying backwards. I think this is friction because if you wear socks, your feet not get enough traction. It's about making sure you have enough traction which I guess is friction at work?

 

[Doc Al]

My question is mainly what is force acting against you that prevents you from flying backwards. I think this is friction because if you wear socks, you will move backwards. It's about making sure you have enough traction which I guess is friction at work?

Sure. For you to push the fridge (or anything else) without sliding backwards, there needs to be sufficient friction acting on you to keep you in place.

When you push the fridge, it pushes back. The friction force on you needs to be enough to counter the force from the fridge.

 

[malemdk]

The friction between your socks and the floor prevents you from flying back and should be greater than the friction between the fridge and the floor if otherwise you will be slipping