A person is able to pull a rope with a force of 700 N. What is the minimum number of fixed and moveable pulleys that the person
will require to lift up a 27,800 N elephant? Assume the pulleys themselves are weightless and the system has 100% efficiency. A. 10 fixed, 10 moveable
B. 15 fixed, 15 moveable
C. 20 fixed, 20 moveable
D. 30 fixed, 30 moveable
the individual requires a mechanical favorable position of 39.7 which is equivalent to 40. A solitary movable pulley gives a mechanical favorable position of 2, two portable pulleys yield a mechanical preferred standpoint of 4, and a framework with three movable pulleys results in a mechanical favorable position of 6. In light of this example, 20 movable pulleys and 20 fixed are required to give a mechanical preferred standpoint of 40
The velocity ratio formula depends on the type of machine. Since the machine in question is a block and tackle system, the velocity ratio will be the number of pulleys in the system.
Using the efficiency formula to get the VR
100 = 39.71/VR × 100
39.71/VR = 1
VR = 39.71
VR = 40(approximately)
This means that the minimum number of pulleys that the person will require to lift the load is 40pulleys i.e 20fixed, 20moveables
A contact force is a force between two objects that are physically in contact with each other: an example of a contact force is the normal reaction of a table supporting a book.
A non-contact force is a force between two objects that are not physically in contact with each other: an example of non-contact force is the gravitational attraction between the Earth and the Moon.
