Question

why does netwon second law is call as real law of motion ? ​

Answer 1

Answer:

Explanation:

This is debatable. Some will agree and some won't.

Newton's second law is a fundamental law of physics (even modern physics) in the form F = dp/dt.

Mathematically, when F = 0 , dp/dt =0. No force, no change in present state of motion (momentum is the quantity of motion in a body). This is the statement of the first law. Hence second law contains the mathematical information which first law can provide. Therefore, some refer it as real law of motion.

Some will oppose this idea because before formulating quantitative description of a phenomena or quantity we seek the qualitative description(both are equally important). First law gives us the qualitative idea (or definition), of what force and inertia(hence mass) are.

The first law describes force as being the cause after change in state of motion and this compels us to describe force as being rate of change of state of motion ( whose measure is momentum).

Hence both laws are important. But from mathematical point of view second law is more important.

I cannot think how second law law can be used to describe third law. Second law describes about the forces to which one particle is subjected whereas third law is the law of interaction between two particles. And third law is not so fundamental as it fails in some basic cases in classical electrodynamics.

We can call F = dp/dt as real law of motion because it sums up the whole theory of motion into one single equation. It is undoubtedly the greatest discovery made by Newton.

thank you..