what distinguishes first class levers from both second and third class levers?
A first-class lever is a lever where the fulcrum is in between the effort and resistance (the load). Seesaws and crowbars are examples of first class levers. A second-class lever is where the resistance is between the effort and the fulcrum. Wheel barrows and wrenches are examples of second class levers. A third class lever is where the effort is between the resistance and the fulcrum. Staplers and your forearm are examples of third class levers. â Mackay, Alan Lindsay (1991). Archimedes ca 287â212 BC. A Dictionary of scientific quotations.