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Past Numericals of Rotational Dynamics for NEB

NEB Past Numericals for Rotational Dynamics 

Here are the past Numericals that were asked by NEB past year . 


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Class 12 The Romance of Physics (Comming soon....) 


 1. A wheel starts from rest and accelerates with constant angular acceleration to an angular velocity of 15 revolutions per second in 10 second calculate the the angular acceleration and angle which the wheel has rotated at the end of 2 second.




2. A ballad dancer spins with 2.4 revolution per second with her arms outstretched when the moment of inertia about the axis of rotation is I with her arms folded the moment of inertia about the same axis becomes 0.6I. calculate the new rate of spin.




3. An electric fan is turned off and its angular velocity decreases uniformly from 500 revolution per minute to 200 revolutions per minute in 4 second . Find the angular acceleration and the number of revolution made by motor in 4 sec interval .



4. A constant torque of 500 Nm turns a wheel which has a moment of inertia 20kgm^2 about its center is 2.5 kgm^2 . Find the Angular velocity gained in 2 second and kinetic energy gained 



5. A disc of radius 1m and mass 5 kg is rolling along a horizontal plane .its moment of inertia about its centre is 2.5 kgm^2 .if its velocity along the plane is 2 m/s .Find its Angular Velocity and the total Energy 




6. A constant torque of 500 Nm turns a wheel about its center . The moment of inertia about the axis is 100 kgm^2 . Find the Angular velocity gaind in 4 second and kinetic energy gained after 20 revolutions 




7. A computer disk is turned on starting from a rest and has a constant angular acceleration .

    a.) how long did it take to make the first complete rotation 

    b.) what is the angular acceleration 

Given that the disk took 0.750 sec for the disk to complete its second complete rotation .




8. A constant torque of 200 Nm turns a wheel about its center . The moment of inertia about the axis is 100 kgm^2 . Find the Angular velocity gaind in 4 second and kinetic energy gained after 10 revolutions 





9. same Question as 2


10. A constant torque of 200 Nm turns a wheel about its center . The moment of inertia about the axis is 100 kgm^2 . Find the kinetic energy gained after 20 revolution when it starts from rest 



11. A ballet dancer spins about a vertical axis at 1 revolution per second with her arm outstreched ,with her arm folded her moment of inertia about the axis decrease by 40% .calculate the new rate of revolution .



12. An electric fan is turned off and its angular velocity decreases uniformly from 500 revolution per minute to 200 revolutions per minute in 4 second . 

  a.) Find the angular acceleration and number of revolution made by the motor in 4 sec interval .

  b.) How many more second are required for the fan to come to rest if the angular acceleration remains constant 

= > Same as the Above Question 3 

13. A disc of moment of inertia 5 x 10^(-4) kgm^2 is rotating freely about the axis through its center at 40 rpm . calculate the new revolution per minute if some wax of mass 0.02 kg is dropped gently on the disc 0.08 m from the axis 



14. same as 10 


15. speed of body spining about the axis increases from rest to 100 rev /min in 5 second . if a constant torque of 20Nm is applied . The external torque is then removed at the body come to rest in 100 sec due to friction . calculate the frictional torque  

  






Thanks for visiting here , May this solution help you in your Study 

Also See 

Class 12 Nepali Book Solution  ,Guide ,Notes  

Class 12 English Book , Guide ,Notes, Solution 


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