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Question
In following figure, shows a system of four pulleys, The upper two pulleys are fixed and the lower two are movable.
- Draw a string around the pulleys. Also show the place and direction in which the effort if applied.
- What is the velocity ratio of the system?
- How are load and effort of the pulley system related?
- What assumption do you make in arriving at your answer in part (c)?
Solution
- Velocity ratio of the system = number of pulleys = 4
- As we know,
M.A. = `"Load"/"Effort"`
As M.A. = n = 4
Substituting the values in the formula, we get,
`"Load"/"Effort" = 4`
Load = 4 × Effort - Part C makes the assumption that the weight of the lower block of pulleys is negligible.
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