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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
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.
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