2.- LEVERS

A lever is a simple machine which has a rigid bar. This bar can pivot on a point of support calls fulcrum. It its used to lift load by applying force to a point on the bar. The applied force calls efford, whereas the load to be lifted is resistance.
The law of lever, which is a consecuence of dynamic equilibriul is E * Ae = R * Ar.
The grater distance between the applied force and the fulcrum, the less efford.
This video shows what you must learn about levers.




ACTIVITIES


1.- Classified this levers and indicate the efford, flucrum and resistance

Scissors, nutcracker, tweezers, wheelbarrow, bottle opener, fishing rod, swing

2.- Imagine you have a lever which one arm double to the other arm. You want to put 20 Kg on one arm and 40 Kg on the other. Where should you position the loads to keep the lever balanced?

HOMEWORK

Sumarize the lesson