Question

When I’m sitting on a chair, the force of the chair on me opposes the force of gravity on me and keeps me from accelerating/falling to the ground. In this example, I do not accelerate to the ground because of which of Newton's Laws?

A. Newton's Third Law: I push on the chair and the chair pushes on me.
B. Newton's First Law: I am not in motion, so I don't continue in motion.
C. Both Newton's Second and Third Laws:
D. Newton's Second Law: The net force on me is 0 (because the upwards force of the chair on me cancels out the downward force of gravity on me), so I do not accelerate.

Answer 1

The scenario of sitting in a chair and not falling is explained by Newton's First Law (law of inertia) and Newton's Third Law (equal and opposite reaction), which together ensure you remain at rest without accelerating downward.

Step-by-step explanation:

When you are sitting in a chair and not accelerating towards the ground, the concept at play is Newton's First and Third Laws of Motion. According to Newton's Third Law, when you exert a downward force on the chair (due to gravity), the chair exerts an equal and opposite upward force on you. This is the chair's normal force that balances out the downward force of gravity. On the other hand, Newton's First Law, also known as the law of inertia, states that a body at rest will remain at rest unless acted upon by an external force. Since the normal force from the chair cancures out gravity, there is no net external force causing you to accelerate; hence, you remain at rest on the chair.