the assembly of two discs as shown  in figure is placed on a rough horizontal surface and the front disc is given an initial angular velocity ' w '. determine the final linear and angular velcity when both the discs start rolling, it is given that friction is sufficeient to sustain rolling in the rear wheel from the starting of motion.

i am  waiting for the reply..........................any one please...........................................                  

hey i cant understand the diagram.. why will the second sphere move?

the front disc is given an initial angular velocity w.

this question is from arihant..............................................

after both the discs start rolling ,          what  is their final linear and angular  velocity.

ans:       angular velocity:   w / 6 ,      

               linear velocity   :  w R / 6 .

any experts ...........please give the solution  ..... .... ............  i am waiting  !!!!!!!!

hey varun,

i solved this using ur equations but i am not getting the answer.

once u try urself,,,,

i didnot understand the first equation    f+T=MA,

becos for the right disc which is rotating with an  angular velocity w ,  the friction acts in the forward direction(i.e, rightward)  and the tension is acting along the string (leftward)......and  hence the equation comes to be

         f - T= MA

even if it is f-T=MA  u wiill not get the answer. first  u try it and then give the reply completely.......

any experts please answer to my question. i am  not getting it.................

i am waiting only for the complete solution.................and not anything else......................

The direction that you show for angular velocity is it correct?

For that direction (clockwise), the right sphere will never collide with the left one as the friction at its point of contact is rightwards.

However if the friction is leftwards, then friction will be rightwards and the right sphere can approach the left one. In that case we will need the distance between the spheres to find with what speed will the left sphere collide with the right one. If the collision be assumed elestic, each sphere gains equal speeds (equal to haf the impacting speed of the left sphere) in opposite directions, but the angular velocity of the left sphere remains at the value it was before collision.

Now, its a simple problem of the spheres being given a vertain configuration of linear and angular velocities and finding their speeds at pure rollning is a standard task.

Please check whether or not the distance between them is given