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Karnataka Board PUCPUC Science Class 11

A Solid Sphere, a Hollow Sphere and a Disc, All Having Same Mass and Radius, Are Placed at the Top on an Incline and Released. the Friction Coefficients Between the Objects

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Question

In the previous question, the smallest kinetic energy at
the bottom of the incline will be achieved by ___________ .

Options

  • the solid sphere

  • the hollow sphere

  • the disc

  • all will achieve same kinetic energy

MCQ
Fill in the Blanks
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Solution

the hollow sphere

Torque is same for all the bodies; therefore, the angular momentum will be conserved.
Now, total kinetic energy = \[\frac{1}{2}m v^2  + \frac{L^2}{2I}\]
So, the body with greater value of moment of inertia will have smallest kinetic energy at the bottom of the incline.

Order of the moment of inertia of the bodies:-
hollow sphere > disc > solid sphere
Hence, the hollow sphere will have the smallest kinetic energy at the bottom.

shaalaa.com
Values of Moments of Inertia for Simple Geometrical Objects (No Derivation)
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Chapter 10: Rotational Mechanics - MCQ [Page 194]

APPEARS IN

HC Verma Concepts of Physics Volume 1 and 2 [English]
Chapter 10 Rotational Mechanics
MCQ | Q 25 | Page 194

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