Perez, Mhon Aldrin H.
ME – 5202
Seatwork No.7
Problem No. 35
During punching process of 350 kg flywheel, the speed varies from 200 rpm to
180 rpm with 1 m mean diameter. Determine the kinetic energy needed.
A. 3.63 KJ B. 6.28 KJ C. 4.51 KJ D. 5.62 KJ
Given:
m = 350 kg
N1 = 200 rpm
N2 = 180 rpm
Dm = 1m
Required:
Kinetic energy
Solution:
Wf 2 2
KE= ( v −v )
2g 2 1
v1 =π ( 1 m ) ( 200 rev
60 s ) =10.47197551
m
s
v 2=π ( 1 m ) ( 180 rev
60 s ) =9.424777961
m
s
350 kg m
KE= (10.471975512−9.4247779612 )
2 s
KE=3646.270515 J =3.646270515 KJ ans. A.