derive the Newton's first law from second law of motion
Answers
NEWTON'S SECOND LAW
According to the Newton’s 2nd Law of motion, the rate of change of linear momentum of a body is directly proportional to the applied external force and in the direction of force.
It means that the linear momentum will change faster when a bigger force is applied.
Consider a body of mass ‘m’ moving with velocity v.
The linear momentum of a body is given by:
p = mv
Now According to Newton’s 2nd Law of Motion:
Force is directly proportional to rate of change of momnetum, that is
F α dp/dt
F = k dp/dt
F = k d(mv)/dt
F = k md(v)/dt
F = k ma
Experimentally k =1
F = k ma
Which is the required equation of force.
NEWTON'S FIRST LAW
The body moves (accelerates) when a force is applied to it that is
F = ma --> a = F / m
When there is no force acting on the body (F = 0), then the body won't move or would remain in motion with constant velocity (won't accelerate in both cases: a = 0), why? Because
a = F / m and F =0 --> a = 0
So we can state the first law: A body will remain at rest or constant velocity unless a force in acted upon it.
Answer:
Newton's first law of motion is an object continues to be in a state of rest or uniform motion along a straight line unless acted upon by an unbalanced force
Explanation:
second law of motion is the rate of change of momentum of object is proportional to the a applied unbalanced force in the direction of the force