Lever resistance (or load). It is common to call the input force "the effort" and the output force "the load" or "the resistance." This allows the identification of three classes of levers by the relative locations of the fulcrum, the resistance and the effort: These cases are described by the mnemonic "fre 123" where the fulcrum is in the middle for the 1st class lever, the "r"esistance is in the middle for the 2nd class lever, and the effort is in the middle for the 3rd class lever. The lever is a movable bar that pivots on a fulcrum attached to
Évelyne Lever specifically for an American audience. She continues to write on and about 18th-century history. French English Évelyne Lever Évelyne Lever (known simply in English as Evelyne Lever) is a contemporary French historian and writer. She was married to a French historian, Maurice Lever, who is the author of "Sade". Lever was previously a research engineer at CNRS, and then began to focus more on 18th-century history. In particular, she focuses on certain people, including Louis XVI, Marie Antoinette and Madame de Pompadour. "Marie Antoinette: The Last Queen of France" was her first book to be published in the United States.