machines [7] [levers] [general] [comprehension quiz]

There are a couple of things you need to know before you start to understand about levers. They are the letters FLE. and The numbers 123. The letters FLE stand for the words FULCRUM LOAD EFFORT. The numbers 1 2 3 stand for the number of "classes" of levers. 1st Class Levers 2nd Class Levers and 3rd Class Levers In a 1st class lever – the fulcrum is in the middle of the effort and the load. In a 2nd class lever – the load is in the middle between the fulcrum and the effort. In a 3rd class lever – the effort is in the middle between the fulcrum and the load. Examples of 1st class levers are: pliers, scissors, crow bar, claw hammer, seesaw, weighing balance, car jack, crowbar, gardening shears, light switch, oars, catapult. Examples of 2nd class levers are: wheelbarrow, nut cracker, bicycle hand brake, bottle opener, car door handle crash bar, door, nail clippers, stapler. Examples of 3rd class levers are: bat, broom, chopstick, golf club, hammer end of a hammer, rake, tennis racket, your arm, tweezers, tongs, stapler, hockey stick.

What do the letters FLE stand for ? fulcrum load energy fulcrum load effort force load effort How many "classes" of lever are there ? 3 4 5 Which of these is a lever ? 1 2 3

There are 9 pictures in a grid. As you hover over each picture a blue screen appears on which there is some information about what is being shown in the picture. Read this information and look at each picture to make sure you understand what is being shown. If you want to check how much you understand try the quiz on the right hand side. To start the activity again just refresh the page.