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Question
In following figure, draw a tackle to lift the load by applying the force in the downward direction.
- Mark in the diagram the direction of load L and effort E.
- If the load is raised by 1 m, through what distance will the effort move?
- State how many strands of tackle are supporting the load?
- What is the mechanical advantage of the system?
Solution
- The load and effort direction are shown in the figure.
-
If the weight travels a distance d in a block and tackle, the effort travels a distance nd.
Where n is the number of pulleys.
∵ Each string is shortened by a length d i.e. dL = d then dE = 1m
∴Effort will move through = 5 × 1 = 5m - Five strands are supporting the load.
- M.A. of system = `"Load"/"Efffort"`
= `(nT)/T`
= n = 5
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