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Question
A pulley system has a velocity ratio of 4 and an efficiency of 90%. Calculate:
(i) the mechanical advantage of the system.
(ii) the effort required to raise a load of 300 N by the system.
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Solution
VR = 4, η = 90%
(i) MA = VR × η%
`=(4xx90)/100=3.6`
(ii) MA =`"Load"/"Effort"`
∴ Effort =`"Load"/"MA"`
`=300/3.6`
= 83.33 N
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A block and tackle system of pulleys has a velocity ratio of 4.
- Draw a labelled diagram of the system indicating clearly the points of application and directions of load and effort.
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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 |
