Advertisements
Advertisements
Question
In the case of a block and tackle arrangement, the mechanical advantage increases with the number of pulleys. Explain.
Advertisements
Solution
With the increase in the number of pulleys in the arrangement of block and tackle, the number of strands of string supporting the load increases and so its mechanical advantage increases.
RELATED QUESTIONS
What is the justification for using the pulley then ?
Name a machine to change the direction of force ?
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 ?
What is a single movable pulley? What is its mechanical advantage in the ideal case?
Give reason for the following:
The lower block of a block and tackle pulley system must be of negligible weight
What is the use of a fixed pulley?
Give reason for the following:
The efficiency of a pulley is always less than 100%
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.
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 |
