NEET 2015 Physics Circular Motion MCQ Question
A mass m moves in a circle on a smooth horizontal plane with velocity v₀ at a radius R₀. The mass is attached to a string which passes through a smooth hole in the plane as shown. The tension in the string is increased gradually and finally m moves in a circle of radius . The final value of the kinetic energy is

mv₀²
mv₀²
2 mv₀²
mv₀²
Correct Answer
Detailed Explanation
As the radius decreases, the angular momentum is conserved. Therefore, the kinetic energy remains the same as mv₀².
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