Question

derive the first law of motion v=u+at

Answer 1

 First equation of Motion:

V = u + at
soln.
Consider a body of mass “m” having initial velocity “u”.Let after time “t” its final velocity becomes “v” due to uniform acceleration “a”.

Now we know that:
Acceleration = change in velocity/Time taken

=> Acceleration = Final velocity-Initial velocity / time taken

=> a = v-u /t
=>at = v-u

or v = u + at
This is the first equation of motion.

Answer 2

Step-by-step explanation:

Newton's first law states that a body stays at rest if it is at rest and moves with a constant velocity unit if a net force is applied on it. Newton's second law states that the net force applied on the body is equal to the rate of change in its momentum.

F = ma

or F = m(v-u) / t

or Ft = mv - mu

That is, when F = 0, v = u for whatever time, t is taken. This means that the object will continue moving with uniform velocity, u throughout the time, t. If u is zero than v will also be zero, i.e., object will remain at rest.