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Question
In the alongside the figure of two pulleys shown a system in which one pulley is fixed and the other is movable. What is the velocity ratio of the system?
An effort of 600 N is needed to lift a weight of 1000 N. What are the mechanical advantage and efficiency of the pulley system?
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Solution
If there are n movable pulleys connected to a fixed pulley, then the velocity ratio is
V.R = 2n
Velocity ratio of the system = 2.
Mechanical Advantage = `"Load"/"Effort"=1000/600`
=`5/3`
Efficiency = `"M.A."/"V.R."`
= `(5//3)/2=5/(3xx2)=5/6`
= 83.3%.
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