Question

A person sitting in a chair in a satellite feels weightless because
A. The earth does not attract the object in a satellite.
B. The normal force by the chair on the person balances the earth’s attraction.
C. The normal force is zero.
D. The person's satellite is not accelerated.

Answer 1

In this question, we need to comment on the weight of the person sitting in a chair in a satellite. For this, we will compare a person sitting in a chair on the Earth’s surface and a person sitting in a chair in a satellite. Compare the normal force and the corresponding force of the gravity.

Complete answer:
-Let us first compare a person sitting in a chair on the Earth’s surface and a person sitting in a chair in a satellite.If a person is sitting in a chair on the Earth’s surface, the person will experience two forces. First is the force of the Earth’s gravitational field. This gravitational force will pull the person downward towards the Earth’s surface.
-Second is the force of the chair. This force will push the person in the upward direction. The upward force of the chair is also referred to as the normal force.If this upward normal force was not present, the person would not have any sensation of the weight.
-This means that without the contact force, that is the normal force, there is no way that the person can feel the non-contact force that is the force of gravity.So, if the normal force is zero, the person cannot feel the force of gravity.Therefore, we can conclude that a person sitting in a chair in a satellite feels weightless because normal force is zero.

Hence, option C is the correct answer.

Note: Students must know that if the normal force is zero, one cannot feel the force of gravity. Students get confused and assume that the person in the satellite is not accelerated. It is due to equilibrium that we can sit on a chair on Earth’s surface as the gravitational force and the upward force to the chair cancels each other.