HISTORY:

Sir Isaac Newton was an English mathematician, physicist, and astronaut. He is considered the founder of the classical mechanic.

Some of his work was focusing on finding the nature of the white light, and the law of gravitation.

In this book:

Philosophiae Naturalis Principia Mathematica was published in 1687. He wrote 3 main laws of motion:

- - First Law:
A body at rest will remain at rest, and a body in motion will remain in motion unless it is compelled to change its state by forces acting on it.
- - Second Law:
The sum of forces, F acting on a body is equal to its mass, m, times its acceleration.
∑F = ma

LAW EXPLANATION

Second Law:

The sum of forces, F acting on a body is equal to its mass, m, times its acceleration.

∑F = ma

Explanation:

According to Aristotle F = m * v (v= velocity)
According to Newton F = m * a (a = acceleration)
So, Newton second’s law states that an object with a velocity maintains that velocity unless a force acts on it to cause acceleration. Note that, acceleration is just a change of velocity.
Newton’s second law is only valid for constant mass systems.
Therefore, An object that is rest will remain at rest unless an external force is excreted upon it.
So, there is force F only if the body is moving/accelerating.

The mathematical explanation is:

Digital Lessons