Question

state and prove work energy theorem by constant force

Answer 1

From Newton’s Second Law of motion, we know that F = ma, and because of the definition of acceleration we can say that



If we multiply both sides by the same thing, we haven’t changed anything, so we multiply by v:



But remember that v = dx/dt:



We rearrange and integrate:

F dx = mv dv



Fx = m(½v2) = ½mv2 = Ek

But Fx = Work; therefore Work = ΔEk

Answer 2

Answer:

suppose a constant force F acting on a body of mass m produces accelaration 'a' in it. After covering distance 's', suppose the velocity of the body changes from u 2 v.

Explanation:

The equation v^2-u^2=2as------- 1

multiplying both side with 1/2m we get---

1/2mv^2-1/2mu^2=mas---2

now from F=ma

1/2mv^2-1/2mu^2=Fs

1/2mv^2-1/2mu^2=W

=Kf-ki=W