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
Mark A. Lever faculty of ETH Zurich. Lever is a member of the Deep Life Scientific Steering Committee and Synthesis Group 2019 for the Deep Carbon Observatory and is an associate editor for "Frontiers in Microbiology". In his research, Dr. Lever investigates factors that determine the presence, abundance, community composition, and metabolism of microorganisms in aquatic sediments and in Earth's crust. In 2013 he discovered that microbes survive deep in the crust by living off of chemical energy in the “dark biosphere.” His work has a special focus on the burial, remineralization, and synthesis of organic matter in aquatic sediments and in Earth’s