Question

A block slides from the top of inclined plane of length 50cm the first 20 cm is smooth and next 30 cm is rough .block is released from rest and again comes to redt from bottom of plane.plane is inclined at 30 degree .find coefficient of friction on rough portion

Answer 1

explanation:as the block is moving downwards so,

net work done =change in kinetic energy

mg sin@(50)-Umg cos@*x=0                      here U= coefficient of friction                            

                                                                       @= inclined angle

                                                                       x= dist travelled due friction

mg sin@(50)=u mgcos@*x

u=tan@/x

  =1/root 3*50/30

   =5/3\/3

5 by 3 root 3