JEE Main 2020 — Rotational Motion Question with Solution
From: JEE Main 2020 (Online) 9th January Morning Slot
Question
One end of a straight uniform 1m long bar is
pivoted on horizontal table. It is released from
rest when it makes an angle 30º from the
horizontal (see figure). Its angular speed when
it hits the table is given as s-1, where n is
an integer. The value of n is _________.
This question includes a diagram. The text above accompanies the figure.
Enter your answer
Show full solutionCorrect answer: 15
Correct answer
15
Step-by-step explanation
By energy conservation
Ui + Ki = Uf + Kf
+ 0 = 0 +
=
n = 15
Ui + Ki = Uf + Kf
+ 0 = 0 +
=
n = 15
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This is a previous-year question from JEE Main 2020, covering the Rotational Motion chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.