You set up a pulley to help you lift something. you anchor the rope at one end and arrange a moveable pulley?

Question

to achieve a mechanical advantage of 2. by the time you have lifted the object 5m off the ground, how much rope have you pulled through the pulley?

Answer 1

Mechanical advantage, distance moved and length of line required with pulleys is a simple mathematical equation.  Simply multiply the distance you need to cover with the mechanical advantage factor and you will get the length of line required.  In this case, 5m x 2=10m of line required (not including enough to go around the pulleys and to hang on to).

Answer 2

try wikipidia/block and tackle. all youll ever need to know. simple math!! not trying to be mean, I do the same thing to my kid!