Isaac newton’s laws of motion

Little did we actually remain ignorance when late Isaac Newton blesses humanity with the fascinating knowledge behind the mysteries of moving particles- concept of motion. Isaac Newton of blessed memory, did not only expose the hidden forces of opposition to movement, he simply demonstrated that humanity has no end should restraint of gravity limitation among others is lifted. Nature would forever be grateful to the proponent of the three sacrosanct laws of motion – (Sir Newton, Philosophiae Naturalis Principia Mathematica, 1687). Each law relates the effect of forces on masses involve in motion. In brief the three laws state:

1.     “An object will remain at rest, or continue to move at a constant motion (velocity), unless it is acted upon by net external force.

2.     The total force experience by an object is equal to its rate of change of the momentum.

3.     For every action there is an equal and opposite reaction”.

It is important to systematically analyze the integral of these laws as separate and intermingling entities.

The first law

This law in a clearer view explains that in the absence of a limiting factor or change or any form of force, an object will continue in its existing state without interruption or damping of capacity. This law is also known as law of inertia – it thus paraphrases “Everybody endures in its state of being at rest or of moving uniformly straight forward, except insofar as it is compelled to change its state by an impressed force. Sometimes scientists refer to it as "zero net force implies zero acceleration". This law rates first in sequential series of the other two laws (Gailili & Tseitlin 2003).

The second law

Summarily,   where:  is the force vector  is mass is the velocity vector  is time

The momentum of an object at motion is given as the product of m and v, the velocity v is taken in the direction of the force or net force for multiple forces. If the rate of change of the velocity is constant with time, momentum is said to occur. For a particle of constant mass m, in modern and classic mechanics, the ‘vectorial’ representation of the second law becomes

F = m a , where F is the force, m is the mass and a is the acceleration. Where;

An Introduction to Mechanics by Kleppner and Kolenkow (n.d.) submits that the second law of motion does not hold for objects of variable mass such as a moving rocket containing fuel and a bucket containing water. Newton can only be expressed when all the constituting masses are integrated. Hence, the second law is only applicable fundamentally to a particle of constant mass.

The third law

“To every action, there occur an equal but opposite reaction both in magnitude and direction.” This simply explains that for a tied car on an anchor attempting to move with an initial automobile force, the reciprocal force of pull is exerted on the car by the anchor. The magnitude of the push is same as that of the pull and it is always in the direction of the exerted force.

Mathematically, MaVa = MbVb where Ma is the mass of the car, Va, the velocity of the car, Mb is the mass of the anchor, and Vb is the gained velocity of the anchor generated by the impulse from the car.


Newton’s laws are contraindicated in the following;

For a massive object. Particles experiencing strong magnetic field, gravitational field, or an electric field. A particle moving with such a high speed or velocity. Substance with optical properties. References

1.  Isaac Newton, The Principia, A new translation by I.B. Cohen and A. Whitman, University of California press, Berkeley 1999.

2.  Galili, I. & Tseitlin, M. (2003), Newton's first law: text, translations, interpretations, and physics education, Science and Education 12 (1): 45-73