A student who weighs 470 N is wearing a backpack that weighs 88 N. The student is standing still on level ground. (a) What is the magnitude of the

A student who weighs 470 N is wearing a backpack that weighs 88 N. The student is standing still on level ground.(a) What is the magnitude of the net force on the student?(b) What is the magnitude of the contact force on the student by the backpack?(c) What is the magnitude of the contact force on the student by the ground?