What is a push or pull that can cause motion known as

Is a push or a pull that causes a moving object to change it's motion; makes objects move or stop; can make an object that is standing still start to move in the direction of the force; can make an object move faster, slow down, stop, or change position. friction.

A force is a push or a pull that causes an object to move, stop, or change speed or direction.  Every time you push or pull something you apply a force. Forces transfer energy.

Explanation: In physics, a force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity, i.e., to accelerate. Force can also be described intuitively as a push or a pull. A force has both magnitude and direction, making it a vector quantity.

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.