posted by Alex .
A pulley system os being used to raise a load. The rope begins at the ceilings, goes down, round a pulley on the load, up to a pulley on the ceiling, back down and around a second pulley on the load, and up to a sheave (a motor driven pulley) on the ceiling. The rope is vertical between the pulleys. The sheave has diameter 90mm and angular 47 rev per min. What is the speed with the load is being raised?
The sheave brings in rope at a rate R*w = .045 m*2*pi*47/60 rad/s = 0.2215 m/s
Since there are four rope strands betqween load and ceiling, the load is raised at 1/4 that rate, 0.0554 m/s