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Question
From the diagram given below. answer the question that follows:
1) What kind of pulleys are A and B?
2) State the purpose of pulley B.
3) What effort has to be applied at C just raise the load L = 20 kgf?
(Neglect the weight of pulley A and friction)
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Solution
1) The pulley A is a single movable pulley and B is a single fixed pulley.
2) Pulley B is a single fixed type pulley. Its purpose is to change the direction of the effort applied.
3) The effort at C is equal to the load. This is because B is a single fixed pulley and its mechanical advantage is 1. So, we have
M.A. = L/E = 1
∴ E = L = 20 kgf
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