how can we rbtain the first law of motion from second law?under what condition?
Answers
Answer: THIS IS COMPLETE EXPLANATION TO YOUR QUESTION. ADD BRAINLIST IF IT REALLY HELPS YOU.
Explanation:
We know,
Newton's second law of motion states that rate of change of momentum of an object is directly proportional to the applied force and takes place in the direction in which the force acts.
Thus,
Force space alpha fraction numerator Change space i n space momentum over denominator Time space taken space end fraction
Thus comma space
F space equals space fraction numerator m left parenthesis v minus u right parenthesis over denominator t end fraction... left parenthesis 1 right parenthesis
Where,
F - Force applied
m - mass
v - final velocity of an object
u = initial velocity of an object
If there is no force acting on the body, the equation (1) can be written as,
0 equals fraction numerator m left parenthesis v minus u right parenthesis over denominator t end fraction
Thus comma space
0 space equals v minus u space
→ v = u ... (2)
This means initial velocity is equal to final velocity when no force acts on the body.
Thus, equation (2) represents Newton's first law of motion.
Newton's first law of motion states that a body at rest will remain at rest and body in motion will remain in motion in staright line with a uniform speed, unless an external force acts on it.
In this way, we can derive Newton's first law of motion from Newton's second law of motion.