Question

24. A person is standing with his arms folded at the
centre of a platform which is rotating about its axis
with kinetic energy of 10 J. Standing at the same
place if he stretches his arms outwards such that
the moment of inertia of the system gets doubled.
The kinetic energy of the system becomes
[NCERT Pg. 157]
e
it
(1) 20 J
(2) 5 J
(4) 40 J
]
(3) 2.5 J​

Answer 1

Answer:

it will help you to understand the topic about the related questions

Answer 2

The answer is 5J

As per question we need to find kinetic energy of the system.

The given data is a person is standing with his arms folded at the

centre of a platform which is rotating about its axis

with kinetic energy of 10 J. Standing at the same

place if he stretches his arms outwards such that

the moment of inertia of the system gets doubled.

We know that the angular momentum conservation rule

The angular momentum conservation rule is

Iω₀ = I₁ω₁

So I₁ =2I

and ω₁=ω₀/2

The initial KE =Iω²₀/2=K

And final KE = I₁ω₁²/2

                     = {2I(ω₀/2)²}/2=K/2

                        = 10/2

                         = 5J

Hence the answer is 5J.

To learn more about energy follow the given link

https://brainly.com/question/1932868?

#SPJ3