Does Static Friction Exist When Gravity is Applied?

AI Thread Summary
Static friction does exist even when gravity is applied to an object on a surface. The forces acting on a stationary object include gravity and the normal force from the surface, which together create the conditions for static friction. Friction only becomes relevant when there is an attempt to move the object, as it resists that motion. The discussion clarifies that the presence of static friction is dependent on the interaction between the object and the surface, not solely on the forces acting on the object. Understanding this concept can help in explaining the dynamics of friction in various scenarios.
stampede247
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Hey guys first time posting and I have a really frustrating question. Is there static friction when the force of gravity is pulling an object straight against a surface. I believe that there is none because (i don't know if I'm wording this right) the friction is equal to the normal of the collision. Let's say you have a 20lb object on perfectly level ground. The only forces acting on the object would be gravity and the reaction force of the ground keeping the object up. Am I right about this. Looking forward to some answers. Thanks.
 
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stampede247 said:
Let's say you have a 20lb object on perfectly level ground. The only forces acting on the object would be gravity and the reaction force of the ground keeping the object up.

Yes those will be the only two forces acting. Friction is only present when there is motion between them mass and the surface.
 
Thank you so much for comfirming that. I had a really long debate with a friend about this and he refused to believe it was true. Now I know how to prove it to him. Thanks for the help.
 

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