Reaction Force

Reaction force is the force exerted by a surface or object when another force acts upon it, based on Newton's Third Law, which states that "for every action, there is an equal and opposite reaction."  This means that when one object applies a force on another, the second object applies an equal force in the opposite direction back onto the first object.

Key Points about Reaction Force

Equal in magnitude  -  The reaction force is always equal in size to the action force.
Opposite in direction  -  It is directed in the opposite direction to the action force.
Different objects  -  The action and reaction forces act on two different objects, not on the same object.

 

Reaction Force Formula
\( F \;=\;  m \; g \; cos(x)  \)
Symbol	English	Metric
\( F \) = Reaction Force	\(lbm\)	\(kg\)
\( m \)  = Mass	\(lbm\)	\(kg\)
\( g \) = Gravitational Acceleration	\(ft\;/\;sec^2\)	\(m\;/\;s^2\)
\( x \) = Angle Between the Ground and the Incline Surface	\(F\)	\(R\)