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प्रश्न
A block and tackle system of pulleys has a velocity ratio of 4.
- Draw a labelled diagram of the system indicating clearly the direction of the load and effort.
- Calculate the potential energy of the load 100 kgf lifted by this pulley to a height 5 m. (g = 10 ms−2)
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उत्तर
a. Pulley drawn correctly with support.
Correct connection of tackle, Marking load and effort with correct direction and tension.
b. U = mgh
= 100 × 10 × 5
= 5000 J
संबंधित प्रश्न
What is a pulley?
Explain how a gear system can be used to obtain gain in speed? Given one example.
What should be the gear ration of a car : equal to 1, less than 1 or greater than 1, while gaining speed on the road ?
In a gear system, the gear ration of the driving wheel A and driven wheel B is 10:1. To rotate the driven wheel B in the direction of driving wheel A, the driving wheel A is engaged with other wheel C. what should be the gear ratio of the wheels A and C?
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.
Fig shown a block and tackles system of pulleys used to lift a load.
(i) How many strands of tackle are supporting the load?
(ii) Draw arrows to represent tension in each stand.
(iii) What is the mechanical advantage of the system?
(iv) When load is pulled up by a distance 1 m how far does the effort end move?
What is a block and tackle system of pulleys?
In the case of a block and tackle arrangement, the mechanical advantage increases with the number of pulleys. Explain.
A boy lifts a load of 40 kgf through a vertical height of 2m in 5s by using a single fixed pulley when he applies an effort of 48 kgf. Calculate:
(i) the mechanical advantage, and
(ii) the efficiency of the pulley. Why is the efficiency of the pulley is not 100%?
(iii) the energy gained by the load in 5s, and
(iv) the power developed by the boy in raising the load.
