Newton’s Second Law

Newton’s second law of motion, also known as the law of acceleration, states that the magnitude of the force acting on an object is equal to the product of that particular object’s mass and the acceleration at which it is moving. This means that the acceleration generated in a body is directly proportional to the force exerted on it and inversely proportional to the mass of the object. The laws of motion were discovered in 1687 by an English mathematician, physicist, astronomer, theologian and author, Sir Issac Newton.

Definition

Newton’s second law of motion tells us about the behaviour of objects, where all the forces present are unbalanced. Moreover, the second law states that the acceleration of an object depends on 2 variables, the total force acting on the object and object’s mass. Acceleration of an object is directly proportional to the net force that is acting on the object and inversely proportional to the mass of the object. So when the force acting on an object increases, as a result of that acceleration of the object also increases. But due to inverse proportionality when an object’s mass increases, the object’s acceleration decreases.

According to Newton’s second law of motion the rate of change of momentum of any body is directly proportional to the total applied force. 

Newton’s first law of motion states that, if there is no net force acting on a body that is at rest, then the body will remain at rest, and if that body is in motion will continue to be in motion.

But here the question comes in mind that, what after if any external force is applied on the body?

Here, Newton states that the velocity of the body will increase or decrease by applying any external force. If the external force is applied on the side of an object, then the direction of velocity changes, which is now termed as acceleration. We call this Newton’s second law of motion.

Formula

Equation of motion is a mathematical formula that describes the position, velocity, or acceleration of a body relative to a specific frame of reference. 

Newton’s second law, which states that the force F acting on a body is equal to the body’s mass m times the acceleration a of its center of mass. F = ma, is the fundamental equation of motion.

If a force is applied to an object, then it will produce acceleration in the body of mass, m and we will mathematically write it as

Force = mass x acceleration

i.e F = ma

acceleration = Force / mass

i.e a = F/m

Derivation of Formula

According to Newton’s second law of motion

a F

And, 

a 1/m

Now, 

a F/m

Therefore, 

F ma

Now, putting K as proportionality constant

F = kma

As we know that in SI unit k = 1

Therefore, 

F = ma

Where, F = Force, m = Mass and a = acceleration

Application of Newton’s Second Law of Motion

Launch of rocket

For a rocket to leave Earth’s orbit and enter space, a force called thrust is needed. According to Sir Issac Newton’s second law of motion, force is proportional to acceleration. Then, to launch a rocket, the amount of thrust is increased, which in turn increases the acceleration. The speed attained by the rocket ultimately helps it escape Earth’s gravitational field and enter space.

Crash of a car

In a car accident, there is a force between the obstacle and the car, called the impact force. The magnitude of the impact force depends on the mass of the objects involved in the collision and the speed at which the objects are moving. This means that the greater the mass of the objects involved in the impact, the greater the intensity of the impact force. Likewise, the greater the acceleration with which the car is moving, the greater the magnitude of the impact force.

Breaking the slab

A karate player uses the second law of motion to accomplish the task of breaking a brick slab. Since, by law, force is proportional to acceleration, the player tends to move their hands quickly across the brick slab. This helps it accelerate and produce proportional force. The force is enough to break bricks.

Walking of two people

Of the two people who are walking, if one is heavier than the other, the one who weighs more walks more slowly because the acceleration of the one who weighs lighter is greater.

Conclusion 

This article describes Newton’s Second law of motion which is one of three Newton’s Laws. And Newton’s Law is the root of classical mechanics. The definition formula application and example everything is written so that you can understand Newton’s Second Law in an easy and simple way. Hope you like this article.