A block sits on the floor what is the magnitude of the

Question

Solve the all parts of given problem:

Problem: A block sits on the floor.

Part A: What is the magnitude of the frictional force on it from the floor?

Part B: If a horizontal force of 5 N is now applied to the block, but it does not move, what is the magnitude of the frictional force on it?

Part C: If the maximum value (fs, max) of the static frictional force on the block is 10 N, and you apply a 12 N force, what is the magnitude of the frictional force?

I need the right answer and steps of solving this problem. Thanks!