Ef157-m5-examsolution-2014-p6 - University of Tennessee

EF 157 -Fall2074-FinalExam-Page I of 7 SectionNo

l) (15 pts) Disk,4, of mass 440 gand radius 3.5 cm, is

initially rotating Counter Clockwise (CCW) at 120

RPM (Revolutions Per Minute) on a frictionless

shaft of negligible radius. DiskB, of mass 370 g

and radius 2.8 cm, is initially rotating Clockwise

(CW) at 550 RPM onthe same frictionless shaft of

negligible radius. DiskB drops freely down onto

diskl and frictional forces bring the two disks to a

common rotational velocity. Treat both disks as

"Solid Cylinders'".

the a) What is the common rotational velocityof together? disks after they come

Initial ff:;l

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- b) What percentage of the initial kinetic energy is lost due to friction? i(

Final

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