Question

A system of pulleys has 4 pulleys in fixed block and 3 in movable block. It is able to lift a weight 45kg with an effort of 20 kg. Find its efficiency.
Answer is 32.14%
I need the solution, plzzz​

Answer 1

hey mate

here is the answer ..

Answer:

velocity ratio(v.r)=the number of pulleys used

=7

mechanical advantage(m.a)=load/effort

=45/20

=2.25

also,

we know that

m.a=efficiency %*v.r/100

=>efficiency %=m.a/v.r*1/100

=>efficiency %=2.25/7*1/100

=>efficiency %=32.1428%