Question

what is third equation of motion

Answer 1

Third equation of motion is
v²-u²=2as

Proof:-
we know that, v=u+at
v-u=at
t=(v-u)/a

distance=average velocity *time
s=(v+u)/2*(v-u) /a
s=(v+u)(v-u) /2a
s=v²-u²/2a
v²-u²=2as

Answer 2

Third equation of motion:-

v² = u² + 2as

Here,

v = Final velocity

u = Initial velocity

a = Acceleration

s = Distance

Explanation:-

Average velocity = v + u / 2

Distance = Average velocity * Time

s = (v + u / 2) t

v + u = 2s / t - (i)

We know that,

v = u + at (first equation of motion)

v - u = at - (ii)

Multiply equation (i) & (ii):-

(v + u)(v - u) = 2s / t * at

v² - u² = 2as

v² = u² + 2as Proved.