Question

why does friction between 2 surface increase when they are pressed harder

Answer 1

friction between two surfaces increase because when we press the object harder then it will apply more force on the surface and the surface will apply more normal force so because friction=uN
then when the normal force increase, friction also increases.
I HOPE IT WILL HELP YOU.

Answer 2

Answer:

Since the friction is due to the interlocking of irregularities in the two surfaces which slide with respect to each other, it increases when the two surfaces are pressed harder.