Advertisements
Advertisements
प्रश्न
You are given four pulleys and three strings. Draw a neat and labelled diagram to use them so as to obtain a maximum mechanical advantage equal to 8. In you diagram make the directions of load, effort and tension in each strand. What assumptions have you made to obtain the required mechanical advantage?
उत्तर
Assumptions:
(i) There is no friction in the pulley bearing.
(ii) The pulleys and the string are massless.
APPEARS IN
संबंधित प्रश्न
A gear system has one wheel with 10 teeth and the other wheel with 50 teeth. Calculate the gain in speed and the gain in torque that you can obtain using them. What will be the gear ration in each case?
A fixed pulley is driven by a 100 kg mass falling at a rate of 8.0 m in 4.0s. It lifts a load of 75.0 kgf. Calculate the power input to the pulley taking the force of gravity on 1 kg as 10 N.
A block and tackle system has 5 pulleys. If an effort 0f 1000 N is needed in the downward direction to raise a load of 4500 N, calculate:
- the mechanical advantage
- the velocity ratio, and
- the efficiency of the system.
In following figure, shows a block and tackle system of pulleys used to lift a load.
- How many strands of tackle are supporting the load?
- Draw arrows to represent tension T in each strand.
- What is the mechanical advantage of the system?
- When load is pulled up by a distance 1 m, how far does the effort end move?
- How much effort is needed to lift a load of 100 N?
- What will be it's V.R. if the weight of the movable block is doubled?
Class I lever can have M.A. = 1, M.A. < 1 and M.A. > 1. Explain each giving examples.
A fixed pulley is driven by a 100 kg mass falling at a rate of 8.0 m in 4.0 s. It lifts a load of 75.0 kgf. Calculate the efficiency of the pulley.
A fixed pulley is driven by a 100 kg mass falling at a rate of 8.0 m in 4.0 s. It lifts a load of 75.0 kgf. Calculate : the height to which the load is raised in 4.0 s.
A single fixed pulley and a movable pulley both are separately used to lift a load of 50 kgf to the same height. Compare the efforts applied in an ideal situation.
A block and tackle system has the velocity ratio 3. Draw a labelled diagram of the system indicating the points of application and the directions of load L and effort E. A man can exert a pull of 200 kgf. If the effort end moves a distance 60 cm, what distance does the load move?
