2- On what factors does Mus and Muk depend?

μs and μk are depend upon the average bond strength between the two surfaces. The normal force along a flat surface is simply equal to the weight of the object, or N = mg. N is an indirect measure of the number of bonds formed between the two surfaces.

myth. it was once thought that animals, including cats and dogs, could only see in black and white. however, scientists have proven this to be a myth. in all animals, including humans, the perception of colour is determined by the presence of cells in the eye called cone photoreceptors.