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Question
What is a pulley?
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Solution
A pulley is an example of a simple type of machine. It is either a wooden or a metallic disc which can rotate about a horizontal axis passing through its centre. It has a grooved rim along which a rope or chain can slide. It is generally mounted in a framework called a block.
RELATED QUESTIONS
A boy uses a single fixed pulley to lift a load of 50 kgf to some height. Another boy uses a single movable pulley to lift the same load to the same height. Compare the effort applied by them. Give a reason to support your answer.
Is the above pulley system an ideal machine or not?
What is the justification for using the pulley then ?
Define the following term in reference to a gear system of Driving gear ?
Define the following term in reference to a gear system for Gain in speed ?
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.
The pulley system shown in the figure is to be used to lift a load W. If the man applying the effort cannot apply a force exceeding 1000 N, what is the maximum load that can be lifted?
The actual load that the man is finally able to lift turns out to be 2700 N. What are the values of the actual M.A., obtained, and the efficiency of the actual set-up?
Name the type of single pulley that has an ideal mechanical advantage equal to 2. Draw a labelled diagram of the pulley mentioned by you.
