Question

A lifting tackle consist of 2 pulley b lock containing 2 and 3 pulley respectively. How mu;st this tackle be use to bbtain the greatest VR? What is the value of this VR?

Answer 1

`VR=5`

Explanation:

From the question we are told that:

No of Pulleys =5

Generally Greatest VR is achieved if it has no friction to the pulleys

Therefore

`W=5P`

Generally the equation for Efficiency is mathematically given by

`n=(MA)/(VR)`

Where

MA=mechanical advantage

Therefore at Greatest VR

`n=100 \%`

`MA=VR`

`VR=(W)/(P)`

`(W)/(P)=5`

`VR=5`