Question

The kinetic energy of a body is 3J and it's moment of inertia is 6kgm². Then it's angular Momentum will be.

options
1) 3kgm²/s
2)6kgm²/s
3)4kgm²/s
4)5kgm²/s​

Answer 1

Answer:

Option (b) 6kgm²/s is required angular momentum .

Explanation:

According to the Question

It is given that ,

• Kinetic Energy,KE = 3J
• Moment of Inertia , I = 6kgm²

we need to calculate the angular momentum of the body .

Here, the kinetic energy is acting in rotational .

Now, calculating the angular momentum

➻ KE = 1/2Iω²

where,

I denote moment of Inertia

ω denote angular velocity

➻ 3 = 1/2 × I × ω²

➻ 6 = 6×ω²

➻ 6/6 = ω²

➻ 1 = ω²

➻ ω = √1

➻ω = 1 rad/s

And,

Now, calculating the angular momentum

• L = Iω

substitute the value we get

➻ L = 6×1

➻ L = 6kgm²/s

So, the required option is (b) 6kgm²/s.

Answer 2

Explanation:

Given :

• Kinetic energy (K.E) = 3 J
• Moment of inertia (I) = 6 kgm²

To find :

• Angular momentum (L)

Solution :

We have,

⟹ 1/2 × Iω² = 3 J

We know,

⟹ L = MVT

⟹ L = Iω

Substituting we get,

⟹ 1/2 × 6 × ω² = 3

⟹ 3 × ω² = 3

⟹ ω = 1 rad/s

Now,

⟹ L = Iω

⟹ L = 6 × 1

⟹ L = 6 Kgm²/s

Answer :

⟹ Angular momentum (L) is 2) 6kgm²/s.