Question

the velocity of a body moving in a straight line is increased by applying a constant force f for some distance in direction of motion prove that the change in kinetic energy of the body is equal to the work done by the force on body​

Answer 1

Answer:

We know that v

2

=u

2

+2as

And Work done =F×s for a constant force F.

Also we know that a =

m

F

v

2

−u

2

=2as

This gives s=

2a

v

2

−u

2

F=ma

We can write work done (W) by this force F as

W=ma(

2a

v

2

−u

2

)=

2

1

mv

2

−

2

1

mu

2

=(K.E)

f

−(K.E)

i