Start Free Mock LoginAlready registered? Login here

Physics - Rotation Question with Solution | TestHub

PhysicsRotationRotational KinematicsMedium2 minPYQ_2020

PhysicsMediumsingle choice

A solid sphere of mass 'M' and radius 'R' is rotating about its diameter. A disc of same mass and radius is also rotating about an axis passing through its centre and perpendicular to the plane but angular speed is twice that of the sphere. The ratio of kinetic energy of disc to that of sphere is

Options:

Answer:

Solution:

Kinetic energy is given by : For sphere $k_{s} = \frac{1}{2} I_{s} ω_{s}^{2}$ For $disc k_{d} = \frac{1}{2} I_{d} ω_{d}^{2}$ $\frac{k _{d}}{k _{s}} = \frac{I _{d} ω _{d}^{2}}{I _{s} ω _{s}^{2}} = \frac{\frac{1}{2} MR ^{2} ( 2 ω ) ^{2}}{\frac{2}{5} MR ^{2} ω ^{2}} = 5$

Stream:MHT_CETSubject:PhysicsTopic:RotationSubtopic:Rotational Kinematics

⏱ 2mℹ️ Source: PYQ_2020

Doubts & Discussion

Loading discussions...