Question

why is it necessary to squares contact force into natural force and frictional force one give reasons​

Answer 1

Answer: Friction always acts to oppose any relative motion between surfaces. Hence it is necessary to separate these two forces as they work in opposite direction in a same body and movement of a body depends on them.

Answer 2

Explanation:

Friction always acts to oppose any relative motion between surfaces. Hence it is necessary to separate these two forces as they work in opposite direction in a same body and movement of a body depends on them.