For most of the surfaces used in daily life, the friction coefficient is less than 1. Is it always necessary that the friction coefficient is less than 1?

In our daily life, we often experience the surface friction which has coefficient μ less than 1. However, it is not necessary that the friction of coefficient is always less than 1. We must have used glass surfaces in day today life. The friction coefficient of glass is 1. Similarly, copper surface also has μ= 1.60 which is greater than 1.


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