Friction or some force acting on momentum of an object

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Friction and air resistance generally decrease the momentum of an object by acting in opposition to its motion. While the absolute value of momentum decreases due to these forces, if the momentum is negative, it can increase. The effect of these forces on momentum also depends on the reference frame; in a moving frame, friction could potentially increase momentum. An example illustrating this is a car accelerating, where friction between the tires and the road propels the car forward, increasing its momentum. Overall, friction typically acts to reduce momentum unless specific conditions alter its effect.
parwana
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Would forces like friction and air resistance increase momentum or decrease it?

I would think if a force acts on momentum it would decrease the momentum of an object. Is that right?

P= mv

P= Ft
 
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It depends on the direction of the force with respect to velocity. In the case of friction and air resistance, the absolute value of the momentum will always decrease, yes.

It should be noted that if the momentum is negative, it will actually increase
 
Of course it would decrease it, but this is assuming a certain refrence frame.
If for some reason the refrence frame were moving, then friction could increase momentum.
 
or I guess it could decrease it and then start increasing it.

<<just to confuse you :) >>
 
I am sure you are familiar with friction decreasing momentum. An example of friction inceasing momentum would be the way a car accelerates. The force that pushes the car forward is actually friction from the road on the tyre. The car accelerates and increases its momentum.
 
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