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प्रश्न
A man raises a load of 360 kgf using a block and tackle system of 3 pulleys. If the efficiency of the pulley system is 60%, what effort is applied by the man?
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उत्तर
Given: L = 360 kgf, E = ?, Efficiency = 60% = 0.6,
Velocity ratio = No. of pulley in the system = 3.
Mechanical advantage (M.A.) = V.R. × Efficiency
= 3 × 0.6
= 1.8
But, M.A. =`"Load(L)"/"Effort(E)"`
∴ Effort (E) =`"Load(L)"/"M.A."`
= `360/1.8`
= 200 kgf.
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संबंधित प्रश्न
Draw a neat labelled diagram showing a pulley being used to lift a load. How are load and effort related in an ideal situation?
Differentiate between a single fixed pulley and a single movable pulley.
Define the following term in reference to a gear system for Gain in torque ?
Give two reasons why the efficiency of a single movable pulley system is not 100%.
The diagram below shows a pulley arrangement.
(i) In the diagram, mark the direction of the forces due to tension, acting on the pulley P.
(ii) What is the purpose of the pulley Q?
(iii) If the tension is T newton, deduce the relation between T and E.
(iv) Calculate the velocity ratio of the arrangement.
(v) Assuming that the efficiency of the system is 100%, what is the mechanical advantage?
(vi) Calculate the value of E
Give reason for the following:
In case of a block and tackle system, the mechanical advantage increases with the increase in the number of pulleys.
In the case of a block and tackle arrangement, the mechanical advantage increases with the number of pulleys. Explain.
What is a block and tackle system of pulleys? What precautions would you observe while rounding the string so that the effort is applied in the downward direction?
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?
