Physics - Rotation Question with Solution | TestHub

PhysicsRotationCalculation of M.I.Medium2 minPYQ_2020

PhysicsMediumsingle choice

Mass per unit area of a circular disc of radius a depends on the distance $r$ from its centre as $σ (r) = A + B r$ . The moment of inertia of the disc about the axis, perpendicular to the plane and passing through its centre is:

Options:

Answer:

Solution:

$σ = A + B r$
$\int d m = \int (A + B r) 2 π r d r$
$I = \int d m r^{2}$
$\int_{0}^{a} (A + B r) 2 π r^{3} d r$
$= 2 π (A \frac{a^{4}}{4} + B \frac{a^{5}}{5})$
$= 2 π a^{4} (\frac{A}{4} + \frac{a B}{5})$

Stream:JEESubject:PhysicsTopic:RotationSubtopic:Calculation of M.I.

⏱ 2mℹ️ Source: PYQ_2020

Doubts & Discussion

Loading discussions...