Final answer:
The measurement of mass in motion is called momentum, which is also another term for Newton's second law of motion. This law states that the net external force acting on an object is equal to the rate of change of its momentum over time.
Step-by-step explanation:
The measurement of mass in motion is called momentum. Momentum is also another term for Newton's second law of motion. Newton's second law states that the net external force acting on an object is equal to the rate of change of its momentum over time. This law can be represented by the equation F = ma, where F is the force, m is the mass, and a is the acceleration.