Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Medical
  • Help me please, - Motion of System Of Particles and Rigid Body - NEET

Two discs of same moment of inertia rotating about their regular axis passing through centre and perpendicular to the plane of disc with angular velocities \omega1 and \omega2. They are brought into contact face to face coinciding the axis of rotation. The expression for loss of energy during this process is:

  • Option 1)

    \frac{1} {2}\text{I}\left( {\omega _1 + \omega _2 } \right)^2

  • Option 2)

    \frac{1} {4}\text{I}\left( {\omega _1 - \omega _2 } \right)^2

  • Option 3)

    \text{I}\left( {\omega _1 - \omega _2 } \right)^2

  • Option 4)

    \frac{\text{I}} {\text{8}}\left( {\omega _1 - \omega _2 } \right)^2

 

Answers (1)

best_answer

Resolving power \varphi \frac{1}{\lambda }

\therefore \frac{R_{1}}{R_{2}}=\frac{\lambda _{2}}{\lambda_{1}}=3:2

 

Law of conservation of angular moment -

vec{ au }= frac{vec{dL}}

- wherein

If net torque is zero

i.e. frac{vec{dL}}= 0

vec{L}= constant

angular momentum is conserved only when external torque is zero .

 

Iw_{1}+Iw_{2} = 2Iw \Rightarrow w=\frac{w_{1}+w_{2}}{2}

\left ( K.E \right )_{i} = \frac{1}{2}Iw_{1}^{2}+\frac{1}{2}w_{2}^{2}

\left (K.E \right )_{f} = \frac{1}{2}\times 2Iw^{2} = I \left ( \frac{w_{1+w_{2}}}{2} \right )^{2}

Loss in K.E = \frac{1}{4}I\left ( w_{1}-w_{2} \right )^{2}


Option 1)

\frac{1} {2}\text{I}\left( {\omega _1 + \omega _2 } \right)^2

This option is incorrect

Option 2)

\frac{1} {4}\text{I}\left( {\omega _1 - \omega _2 } \right)^2

This option is correct.

Option 3)

\text{I}\left( {\omega _1 - \omega _2 } \right)^2

This option is correct

Option 4)

\frac{\text{I}} {\text{8}}\left( {\omega _1 - \omega _2 } \right)^2

This option is incorrect

Posted by

divya.saini

View full answer

NEET 2024 Most scoring concepts

    Just Study 32% of the NEET syllabus and Score up to 100% marks

Similar Questions

Trending Articles/News

anam-khan

Education ministry, IIT Kanpur launch 30-day free crash course ‘SATHEE’ for NEET 2025 preparation
anam-khan

NTA 'lapses' in NEET UG 2024: SC closes case as Centre assures to implement suggested reforms
anam-khan

Is NEET admit card 2025 out? Exam city intimation slip on April 26, hall ticket on May 1

Latest Question