Question

the length of the load arm of a lever is 6m long and the effort arm is 3m long what is a effort required to lift a load of 40N

Answer 1

MA = EA/LA
= 3/6
=1/2

MA =L/E
E=L/MA
  = 40*2
 = 80N

Answer 2

Length of the Load arm=6m

Length of the Effort arm=3m

Force created by the Load=40N

If,

Mechanical Advantage - Load/Effort=Load Arm/Effort Arm

Then,

Effort=40N/x=3m/6m

or,x*3=40*6

or,x=40*6/3

or,x=80N