How to distinguish the classes of lever

References

1. Animation http://sg.video.search.yahoo.com/video/play;_ylt=A2oKiKbwpTJRL2wAKh5O4gt.;_ylu=X3oDMTBrc3VyamVwBHNlYwNzcgRzbGsDdmlkBHZ0aWQD?p=teach+levers&vid=8a032be44e22e1cdcdf0f3f8fabe1e11&l=2%3A17&turl=http%3A%2F%2Fts4.mm.bing.net%2Fth%3Fid%3DV.4651149861650727%26pid%3D15.1&rurl=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DD23IZxYaLHs&tit=Lever+-introduction+to+3+types+-+Simple+Machines+lesson+for+kids+...&c=3&sigr=11adt01a8&fr=yfp-t-712

Classes of levers

Classes of lever

There are three basic types of lever in mechanical systems:

A lever is a simple tool to increase a force to allow a difficult action to be performed more easily. There is a weight to be moved or lifted, a lever, the fulcrum or pivot point, and the force applied. I
In the image above, we find the three types of levers that are used in daily activities.
In a class 1 lever, the fulcrum is in the middle and a downward force on one end creates lift at the other. Examples of this include a see-saw, where the load and the force are interchangeable, opening a paint can with a screw driver, or prying a large boulder out of a hole.
A wheel barrow is a typical class 2 lever. The fulcrum, a wheel, is at the end, the load is in the middle, and the effort or force lifts up against the weight.
Class 3 is like class 2 with the effort and load reversed. Hitting a baseball with a bat or a tennis ball with a racket, with the wrists as the fulcrum and the ball as the load.