The product of mass and acceleration defines which physical quantity?

The product of mass and acceleration defines force according to Newton's second law of motion, which states that force is equal to the mass of an object multiplied by its acceleration (F = ma). This relationship highlights how an object's mass and the rate at which its velocity changes (which is acceleration) combine to affect the net force applied to it.

In this context, energy, momentum, and power are related concepts but do not fit the specific definition of mass times acceleration. Energy is the capacity to do work, momentum refers to the product of an object's mass and its velocity, and power is the rate at which work is done or energy is transferred. Thus, the correct identification of the quantity defined by the product of mass and acceleration is indeed force.