A block and tackle system has 4 Pulley to lift the load of 840 Newton through a distance of 12 metre the weight of the movable Pulley is 20 Newton

Asked by shashwat12pandey | 15th Mar, 2021, 03:12: AM

Expert Answer:

Effort E to lift the load L = 840 N is given as
 
E = ( L+w ) / n
 
where w is weight of moveable pulley and n is number of pulleys
 
Hence Effort E = ( 840+20)/4 = 215 N
 
Mechanical advantage , MA = n - (w/E) = 4 - (20/215) = 3.907
 
Efficiency η = 1 - [ w / ( nE ) ]  = 1 - [ 20 / ( 4 × 215 ) ] = 0.977

Answered by Thiyagarajan K | 15th Mar, 2021, 08:28: AM