If the Moment of inertia, rotational kinetic energy, and angular momentum are given by M, K, and L, then:

This question was previously asked in
HPCL Engineer Mechanical 04 Nov 2022 Official Paper (Shift 2)
View all HPCL Engineer Papers >
  1. K = 2 LM
  2. L = √(2 MK)
  3. M = K/L
  4. L = MK

Answer (Detailed Solution Below)

Option 2 : L = √(2 MK)
Free
Soil Mechanic for All AE/JE Civil Exams Mock Test
7.4 K Users
20 Questions 20 Marks 20 Mins

Detailed Solution

Download Solution PDF

Concept:

Angular momentum: The angular momentum of a rigid object is defined as the product of the moment of inertia and the angular velocity. Angular momentum also obeys the law of conservation of momentum i.e. angular momentum before and after is conserved.

Angular momentum, L = M × ω

Rotational kinetic energy: For a given fixed axis of rotation, the rotational kinetic energy is given by:

\(KE = {1\over 2 }* M\omega^2\)

Where M is the moment of inertia, ω is the angular velocity.

Calculation:

Angular momentum, L = M × ω.

Rotational Kinetic Energy K \(= {1\over 2 }* M\omega^2\) ⇒ \(\omega = \sqrt{2K \over M}\)

Therefore, \(L = M * \sqrt{2K \over M} = \sqrt{2MK}~\)

Latest HPCL Engineer Updates

Last updated on Jun 2, 2025

-> HPCL Engineer 2025 notification has been released on June 1, 2025.

-> A total of 175 vacancies have been announced for the HPCL Engineer post in Civil, Electrical, Mechanical, Chemical engineering.

-> HPCL Engineer Online application will be activated from 1st June 2025 to 30th June 2025.

-> Candidates with a full-time engineering discipline in the relevant stream are eligible to apply.

-> The selection will be based on a Computer Based Test Group Task and/or Interview. Prepare for the exam using HPCL Engineer Previous Year Papers.

More Moment of Inertia and Centroid Questions

Get Free Access Now
Hot Links: teen patti glory teen patti live teen patti master teen patti wala game