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प्रश्न
Rohan exerts a pull of 150 kgf. What is the maximum load he can raise with this pulley system if its efficiency = 75%?
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उत्तर
Given that
Velocity ratio, VR = 5
Effort = 150 kgf
Efficiency = 75%
We know that efficiency, `eta = "Mechanical Advantage"/"Velocity Ratio"`
`75/100 = "MA"/5`
`Ma = 5 xx 75/100`
∴ Mechanical advantage = 3.75
But, Mechanical advantage = `"Load(L)"/"Effort(E)"`
∴ Load = Mechanical advantage x Effort
= 3.75 x 150 Kgf
= 562.5 Kgf
Therefore, Rohan can raise a maximum load of 562.5 kgf with this pulley system
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संबंधित प्रश्न
What is the justification for using the pulley then ?
Answer the following in short.
Explain the various functions that a machine can perform.
Explain how a gear system can be used to obtain gain in torque? Given one example.
The diagram below shows an arrangement of three pulleys A, B, and C. The load is marked as L and the effort as E.
- Name the Pulleys A, B, and C.
- Mark in the diagram the directions of load (L), effort (E) and tension T1 and T2 in the two strings.
- How are the magnitudes of L and E related to the tension T1?
- Calculate the mechanical advantage and velocity ratio of the arrangement.
- What assumptions have you made in parts (c) and (d)?
Give reason for the following:
In a single fixed pulley, the velocity ratio is always more than the mechanical advantage.
Give a reason for the following:
In a single fixed pulley, the velocity ratio is always more than the mechanical advantage.
Name a machine which is used to:
change the direction of force applied.
A type of single pulley is very often used as a machine even though it does not give any gain in mechanical advantage. For what purpose is such a pulley used?
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?
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)
