What is the formula for friction force

For the question about friction force impeding motion. I'm sorry I tried what you wrote and did not...

A 2.40 kg mass, m, on a frictionless table is moving in a circle with radius 0.500 m at a constant s...

a box is sliding down a frictionless plane inclined at an angle of 30 degrees with the horizontal. w...

Assume that there is no friction between m2 and the incline, that m2 = 2.4 kg, m1 = 1.2 kg, the radi...

Assume that there is no friction between m2 and the incline, that m2 = 1.8 kg, m1 = 1.4 kg, the radi...

Assume there is a large frictional force acting on the cart (coefficients of friction 𝜇𝑆 = 0.4 and 𝜇...

In which direction does friction act?

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