Question

1. What is a machine?    
2. The figure below shows a pulley system.
   
   1. State the velocity ratio of the pulley system,  
   2. Explain what happens to the mechanical advantage of the machine as the load is increased gradually:
3. If an effort of 150N is used to raise a load of 450N using the pulley system in (2) above. 
   1. Determine its Mechanical advantage   
   2. The efficiency of the pulley.   

Answer 1

1. A device that enables work to be done more easily or conveniently
2.  
   1. 3
   2. Mechanical advantage increases with the load and becomes constant and maximum load the machine can support.
3.  
   1. M.A = L  = 950N = 3
                E     150N
   2. Efficiency =M.A × 100
                         V.R
                    =³/₃ × 100
                    =100