Simple Machines

Which Simple MAchine is this?
 
Pulley
Effort
What force does the boy act as?
 
Pulley
Effort
What force are the books
 
Pulley
Effort
{"name":"Simple Machines", "url":"https://www.quiz-maker.com/QPREVIEW","txt":"Which Simple MAchine is this?, What force does the boy act as?","img":"https://cdn.poll-maker.com/16-668389/moveable-pulley-2.png?sz=1200-00000015911000005300"}
Powered by: Quiz Maker