Question

Tha mass of the body is halved and its speed is doubled.
What happens to the kinetie energy of the body?​

Answer 1

Answer:

We know that, KE = ½mv².

Now, here mass is halved. Hence, mass = m/2.

And the velocity is doubled. Hence, velocity = 2v.

Substituting the new values in the formula : ½*m/2*k2v)²

Solving the equation :

⇒ ½*m/2*(2v)²

⇒ ½*m/2*2v*2v

⇒ mv²

Hence, the KE is doubled.

Kinetic Energy is the energy of am object possessed aur to motion.

It is said to be proportional to mass and square of velocity.

We know that, Work Done = Force × Displacement.

⇒ Work Done = ma × s

(Force = ma)

Now, We know that : v² - u² = 2as

Hence, as = v² - u²/2

Substituting :

⇒ Work Done = m (v² - u²/2)

⇒ Work Done = ½mv² - ½mu²

The work done at initial should be 0, hence :

⇒ Work Done = ½mv²

Now, we know that Work Done is Kinetic energy.

Hence, KE = ½mv².