Question

1. name the missing force.... a) frictional force b) normal force c) tension force d) weight force student fg

Explanation:

The gravitational force ($F_g$) acts downwards on the student. According to Newton's third - law, when the student is sitting on the chair, the chair exerts an upward force on the student. This upward force perpendicular to the surface of contact is the normal force.

Answer:

b) normal force