Question

The figure below shows a pulley system.

1. What is the velocity ratio of the system? 
2. Calculate the efficiency of the system.
3. Give one reason why efficiency is not 100%. 

Answer 1

1. VR=3
2. N=MA/VR x 100
   400/150 x 100%
            3
   = 88.88%
3.   
   • Friction between the movable parts of the pulley.
   • Work is done in lifting the movable parts of the pulley system.