Newton’s Second Law of Motion


Effect of net force and mass on acceleration

Let us see how net force and mass impact acceleration.

●     Net force and acceleration

 Suppose there’s an object on a table and a net force of 10 units is applied on it. Then a net force of 20 units is applied to it. In which case will the acceleration be more? The one in which the force was more.

Thus, we can say that, the more the force, the more the acceleration is and the lesser the force, the lesser the acceleration is.

●     Mass and acceleration

 Let’s say there are two objects on a table. One has a mass of 3 kg, and the other has a mass of 5 kg. If a net force of 10 units is applied to each of them, which one will accelerate more? The one with a mass of 3 kg because it has a lesser mass.

Thus, we can say that, the lesser the mass, the more the acceleration is and the greater the mass, the lesser the acceleration is.

Based on the above observations, we can say that acceleration is directly proportional to the net force applied and inversely proportional to the mass of the object.

Newton’s second law of motion

The above relationship of acceleration, net force and mass can be written as:

a = 𝐹𝑛𝑒𝑡/𝑚→ Fnet = m x a

Thus, the net force acting on an object is equal to the mass of the object times its acceleration. This is nothing but Newton’s second law of motion.

What is the unit of force?

The standard unit of mass is kg, and that of acceleration is m/s2. So, the unit of force is kg m/s2, which is called Newton.

One unit of Newton is defined as the amount of force required to give a 1 kg mass an acceleration of 1 m/s2.