Question

A lever with an output arm of 0.8 meter has a mechanical advantage of 6. What is the length of the input

Answer 1

From the law of the lever: 

mechanical advantage= input arm : output arm

input arm- a
output arm-b
$mechanical\ advantage= 6\\\\ 6=\frac{a}{0,8}\ \ |*0,8\\\\ 6*0,8=a\\\\ a=4,8m$
Input arm is equal 4,8m