A 100 Newton force applied to a machine lifts a 400 N object. What is the actual mechanical advantage of
this machine?

m = 4

Explanation:

It is given that,

A 100 Newton force applied to a machine lifts a 400 N object.  

We need to find the mechanical advantage of  this machine.

The mechanical advantage of a machine is given by the ratio of output force to the input force.

Here, output force is 400 N and input force is 100 N

So, mechanical advantage becomes :

So, the mechanical advantage of this machine is 4.