Shane observes that an upward force pushes him up when he sits on a chair. Based on his observation which statement is correct

Friction can act at a distance.

Normal force can act at a distance.

The chair applies a non-contact force called friction.

The chair applies a contact force called normal force.

Option - (D) : The chair applies a contact force called normal force.

Explanation:

Normal Force, Fn:

When the person sits on the chair he experience an upward force just because there is net force or opposition to the object having some mass, m placed on a given surface area. As there will be force applied in opposite direction to that of applied by the body in the downward direction. Normal force is always found opposite in direction, but the magnitude of the normal force is not much or it is far less then force applied by the body on the given surface.

Shane observes that an upward force pushes him up when he sits on a chair. Based on his observation, he understands that the chair applies a contact force called "normal" force.