Question

urgent please answer asap​

Answer 1

Answer:

#Red official

Follow me.

$I_{1}\omega_{1} = I_{2}\omega_{2}$

Apply this formula and get ur answer.

Answer 2

11th/Physics

Rotational mechanics

Answer :

★ Disc A :

• Mass = M
• Radius = R
• Initial angular velocity = ω

★ Disc B :

• Mass = M/2
• Radius = R
• Initial angular velocity = 0

Disc B is placed gently on the Disc A. We have to find final angular velocity of the system$.$

⧪ Here, no external torque acts on the whole system therefore angular momentum (L) is conserved.

Moment of inertia of uniform circular disc of mass M and radius R about axis passing through the centre and perpendicular to the plane is given by

• I = MR²/2

★ MI of disc A :

➙ I₁ = MR²/2

★ MI of disc B :

➙ I₂ = (M/2)R²/2

➙ I₂ = MR²/4

Let's apply concept of angular momentum conservation :D

➤ L (initial) = L (final)

➤ I₁ω₁ + I₂ω₂ = (I₁ + I₂)ω'

➤ MR²ω/2 = (MR²/2 + MR²/4)ω'

➤ MR²ω/2 = 3MR²/4 × ω'

➤ ω/2 = 3ω'/4

➤ ω' = 2ω/3

Hence, (D) is the correct answer.

Cheers!