What’s does “co efficient of friction” mean and how is it different from Friction Force?
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When you drag an object along a flat floor, the friction you have to overcome depends on how hard the object is pushing itself into the floor. In other words, it depends on the object’s weight: the heavier the object, the more friction there is, assuming that we’re keeping the materials the same. It turns out that, for practical purposes, the friction is almost exactly proportional to the weight: double the weight, you double the friction; divide the weight by 3 and you divide the friction by 3.
General math fact: when two things are proportional, you can write an equation: one of them equals some constant value times the other. In this case, we have weight and friction proportional, so we can write Friction Force = k * Weight. But of course the value of *k* (which is just some number that depends on the materials involved) here matters: if *k* is very small, then the friction is small even if the weight is very large. If *k* is very big, the friction is big even if the weight is pretty small.
The number *k* in this equation is the *coefficient of friction*. It describes how high the friction force is *relative to the weight of the object*. A material that has lots of friction relative to its weight has a high coefficient of friction; a material that has less friction relative to its weight has a low coefficient of friction.
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