What is the sum of the forces in an action reaction pair? a. always less than zero b. always greater than zero c. always equal to zero d. sometimes less than zero

The sum of the forces in the pair of action and reaction forces are always equal to zero.

Answer : Option C

Explanation:

The action force when applied to the surface or body, in contact, produces a reaction force. This reaction force is produced in an strength or force equal to that of the action force applied as a pure form of reaction and is opposite to the direction of the action force applied.

Hence the action force and reaction force are opposite in their application and so by the convention, the action force gets positive force and reaction force gets negative force.

Sum of action reaction force pair = action force - reaction force = 0.

gas and liquid

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.