Conceptional doubts in making FBDs

[Deep Blue]

Homework Statement

I just have some conceptional doubts and it would really be appreciated if some one would answer!
Q1. What is net contact force?
Q2. Does it have friction as one of its components?
Q3. Is it any way similar to normal force?

Homework Equations

The Attempt at a Solution

I did try to read through Halliday Resnick Jearl Walker Physics textbook, but I wasn't satisfied.

 

[ehild]

Homework Statement

I just have some conceptional doubts and it would really be appreciated if some one would answer!
Q1. What is net contact force?
Q2. Does it have friction as one of its components?
Q3. Is it any way similar to normal force?

When speaking about contact force in Mechanics, it usually includes both the normal force and friction.
Do you have any special problem?

ehild