Answer:
Explanation:
There is change in moment of inertia of turntable due to which its angular velocity changes . We shall apply law of conservation of angular momentum
initial moment of inertia = 1 / 2 M r² , M is mass and r is radius of table
I₁ = 1/2 x 2.1 x .10²
= .0105 kg m²
final moment of inertia
I₂ = I₁ + 2 x m r² , m is mass of fallen blocks on the table
= .0105 + 2 x .52 x .1²
= .0105 + .0104
= .0209 kg m²
initial angular velocity ω₁ = 2π n , n is revolution per second
= 2π x 70 / 60
= 2.3333 π rad /s
Final angular velocity ω₂ = ?
Applying law of conservation of angular momentum
I₁ ω₁ = I₂ ω₂
.0105 x 2.3333 π = .0209 x ω₂
ω₂ = 1.172 π
= .586 x 2 π rad / s
no of revolution per sec = .586
no of revolution per minute = .586 x 60
= 35.16 rpm .