Question

Derivation of kinetic energy....?

Answer 1

derivation for the expression of kinetic energy,

v²-u²=2as

here intially the object is at rest so u=0

v²-0²=2as

v²=2as

 s=v²/2a...........................{1}

now work done=force ×displacement

              w=f×s

              w=m×a×v²/2a

              w=mv²/2

here the work done stored in the kinetic energy,

         K.E= mv²/2

Answer 2

Answer:

Work done by the force = force × displacement ... (1)

By Newton's 3rd equation of motion(2)

$\frac{ {v}^{2} - {u}^{2} }{2as}$

By 2nd law of motion (3)

$f = m \times a$

from 1 , 2 and 3 we get ...

w = ma (v²-u²)/2a

if u = 0 then , w= ½mv²

This work done is stored in Ke ...

ke = ½mv²