Question

Suppose you are holding a box in front of you and away from your body by squeezing the sides, as shown in (Figure 1) .

Part A

Choose the correct free-body diagram showing all of the forces on the box

What is the force that is holding the box up, the force that is opposite the weight force?

normal force
	kinetic friction force
	gravitational force
	static friction force

Answer 1

here,

Normal force is the component, perpendicular to the surface (surface being a plane) of contact, of the contact force exerted on an object by, for example, the surface of a floor or wall, preventing the object from falling.

Static frictional force = minimum force to hold movement of box.
it always act opposite to force resulting in motion of body.
Here it is acting againt force due to gravity

PART A :
by following above theory Diagram 3 is correct

PART B:
by following above theory, force resposible for still motion is Static frictional Force.