Difference Between Force and Momentum
Momentum, in physics, defined as the mass of a body multiplied by its velocity. For example, an automobile weighing 2,500 pounds (1,134 kg) traveling in a straight line at 88 feet per second (60 miles per hour, or 26.82 meters per second) has a momentum of 2,500 × 88 = 220,000 foot-pounds (30,414 kilogram-meters) per second. If two bodies have the same mass and the same velocity, then they have the same momentum. If the two bodies have the same mass and are traveling at different velocities, then the one that is traveling faster has the greater momentum. If the two bodies have different masses but are traveling at the same velocity, then the more massive one has the greater momentum.
Force, one of the most useful concepts in physics. In everyday life we have an intuitive notion of force as a push or a pull on an object. We push on objects, and they move; the earth’s gravitational pull causes unsuspended objects to fall; frictional forces cause sliding objects to slow and eventually stop; a struck baseball moves off abruptly from the bat; and the force exerted by the engines of a jet aircraft causes it to move at high speed. Such familiar examples of the manifestations of force are innumerable. Indeed, ideas brought to mind by the word “force” are so natural to us that it is difficult to overcome intuitive notions and arrive at a rigorous definition of force.
Concept of Force in Physics
In physics the concept of force denotes a quantity and it therefore must be subject to some kind of measurement to make the concept meaningful.
How Force Is Measured
Instruments used in measuring force include the spring balance, the torsional balance, the gravitational balance, and piezoelectric devices. The spring and torsional balances, which are calibrated in terms of known forces, measure a particular force in terms of the mechanical distortion of a material object. The gravitational balance compares a given force with the gravitational pull of the earth. Piezoelectric devices have crystals that produce measurable electrical voltages when subjected to forces.