Natural science review

Well, children, this is  your task for natural science today:


Look at these pictures and RECOGNISE  the elements taking part in every invention (= in the lever,  in the screw… in all of them):
- where is the load ? (in every picture the load is different)
- what does the effort consist in? (in every picture the effort is different to get the objective)
- what is the benefit of using each machine (different benefits) ?