Prove that second law of motion is the real law of motion
Answers
(i) First law is contained in second law: According to Newton’s second law of motion,

It means that there will be no acceleration in the body if no external force is applied. This represents that a body at rest will remain at rest and a body in uniform motion will continue to move along the same straight line in the absence of an external force. This corresponds to Newton’s first law of motion. So, first law of motion is contained in Second law of motion
Newton's second law of motion
The second law of motion stated that "Acceleration of an object produced by net force is directly proportional to the magnitude of that net force and inversely proportional to the mass of the object if it is in the same direction of the net force".
The second law of motion is related to the behaviour of the objects to which there is Not balanced force. Writing this law in the form of equation, then it can be written as:
a = F / m
In simple terms, The same equation is written as:
F = m * a
"The most important thing to be remember in the 2nd equation of Motion is NET FORCE"
The direction of the Net force is in the same direction of acceleration. Hence, The direction of Acceleration and Net force is always same. So, if the net force is given or known, then indirectly we know about the acceleration also.
Problems based on Second Law of Motion:
- Net Force and Mass is given; we have to find acceleration.
Acceleration = Net force / Mass
- Mass and Acceleration is given; we have to find net force.
Net force = Mass * Acceleration
- Acceleration and Net force is given; we have to find Mass.
Mass = Force / Acceleration
Q. If the net force is 10 and mass 2 KG, find the acceleration ?
=> We know that,
Acceleration = Net force / Mass
Acceleration = 10 / 2
Acceleration = 5
Therefore, Acceleration is 5.
Problems based on Newton's second law are in this way.