An object in the vacuum of space orbits the earth at a fixed speed in a circular orbit several

hundred miles above the earth. What can we conclude about the reaction force?
a) That there is no reaction force-the net force on the object is zero, so the reaction
force is zero too.
b) The reaction force is a force that acts on the earth directed upward toward the object.
c) There is no reaction force- there’s a net force on the object, but zero reaction force because the
object is out in space.
d) The reaction force is a normal force that acts upward from the Earth’s surface.

The reaction force is equal and opposite to the weight force that acts on the object. That is what Newton's third law would say about the reaction force. Now, make your selection.

The correct answer is (b) The reaction force is a force that acts on the earth directed upward toward the object.

To understand why, we need to consider Newton's third law of motion, which states that for every action, there is an equal and opposite reaction.

In this scenario, the object in orbit is experiencing a centripetal force towards the Earth, which keeps it in circular motion. According to Newton's third law, there must be an equal and opposite reaction force acting on the Earth.

The reaction force acts on the Earth and is directed upward toward the object. This is because the object's motion pulls the Earth slightly toward it. Though the effect on Earth is minuscule due to its massive size, it still experiences a reaction force in the opposite direction.

Therefore, the correct conclusion is that the reaction force is a force that acts on the Earth directed upward toward the object.