Question

what is three equation of motion

Answer 1

s =ut+1/2atsquare
v=u+at

Answer 2

 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.

Second equation of motion:
s = ut + 1/2 at^2
Let the distance travelled by the body be “s”.
We know that
Distance = Average velocity X Time
Also, Average velocity = (u+v)/2
.: Distance (t) = (u+v)/2 X t …….eq.(1)
Again we know that:
v = u + at
substituting this value of “v” in eq.(2), we get
s = (u+u+at)/2 x t
=>s = (2u+at)/2 X t
=>s = (2ut+at^2)/2
=>s = 2ut/2 + at^2/2
or s = ut +1/2 at^2
This is the 2nd equation of motion

Third equation of Motion
v^2 = u^2 +2as
We know that
V = u + at
=> v-u = at
or t = (v-u)/a ………..eq.(3)
Also we know that
Distance = average velocity X Time
.: s = [(v+u)/2] X [(v-u)/a]
=> s = (v^2 – u^2)/2a
=>2as = v^2 – u^2
or v^2 = u^2 + 2as
This is the third equation of motion