184k views
17 votes
By lubricating the pulley, the work needed was decreased from 50 J down to

44 J. The output work of the pulley remained 40 J.
The efficiency of the pulley AFTER lubrication is

1 Answer

10 votes

Before lubrication:


\tt (40)/(50)* 100\%=80\%

The efficiency of the pulley after lubrication becomes:


\tt (40)/(44)* 100\%=91\%

User Fernando Moreira
by
3.8k points