A pulley system has an efficiency of 74.2%. If you perform 200 J of work, how
much useful work does the pulley perform?
A. 52 J
B. 113 J
C. 148 J
D. 200 J
SUBMI
If a pulley system has an efficiency of 74.2%, then only that fraction of the work performed will be useful. 74.2%=0.742. 0.742*200 is about 148J. Hope this helps!
