A box rests on a frictionless countertop. A boy pushes horizontally to the right on the box, and a girl pushes on it to the left, yet it remains stationary. Which of the following statements is false?
A) We know the force of the boy on the box is equal in magnitude to the force of the girl on the box, because the box is in equilibrium.
B) We know the force of the boy on the box is equal in magnitude to the force of the box on the boy, because of Newton's third law.
C) We know the weight and normal force are equal in magnitude because the box is in equilibrium.
D) We know the weight and normal force are equal in magnitude because of Newton's third law.

Question

Quizplus · Accepted Answer

Option D is false. Weight and normal force are not related to Newton's third law. The normal force is a reactive force that arises as a result of the contact of two surfaces, and is perpendicular to the surface. The weight is a gravitational force that pulls an object down towards the center of the Earth.

A Box Rests on a Frictionless Countertop