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Question
A block and tackle pulley system has a velocity ratio 5. Draw a labelled diagram of this system. In your diagram, indicate clearly the points of application and the directions of the load and effort.
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Solution
RELATED QUESTIONS
What is the justification for using the pulley then ?
Answer the following in detail.
How does a pulley make work simpler?
Define the following term in reference to a gear system for Driven gear ?
What should be the gear ration of a car : equal to 1, less than 1 or greater than 1, while ascending a hill ?
Give reason for the following:
In a single fixed pulley, the velocity ratio is always more than the mechanical advantage.
In the case of a block and tackle arrangement, the mechanical advantage increases with the number of pulleys. Explain.
The alongside figure shows the combination of a movable pulley P1 with a fixed pulley P2 used for lifting up a load W.
(i) State the function of the fixed pulley P2.
(ii) If the free end of the string moves through a distance x, find the distance by which the load W is raised.
(iii) Calculate the force to be applied at C to just raise the load W = 20 kgf, neglecting the weight of the pulley P1 and friction.
A ‘block and tackle’ system used 3 pulleys in the lower block and 4 pulleys in the upper block. What is the ‘velocity ratio’ of this system? If the load is to be lifted by a person capable of applying a maximum effort of 1000 N, what is the maximum load than can be lifted under ideal conditions?
The actual maximum load that gets lifted turns out to be 6300 N. What are the values of the actual M.A. and efficiency of the set-up?
Complete the table.
| S. No | Types of Simple Machine | Example |
| 1. | Pulley | |
| 2. | Wheel and axle | |
| 3. | Wedge | |
| 4. | Inclined plan | |
| 5. | Lever | |
| 6. | Screw |
State one advantage of single movable pulley.
