The four polders with their areas of fertile soil would be: (I) North-west polder, area 53,599 acres; fertile soil, 46,189 acres.
A lever (/ËliËvÉr/ or US /ËlÉvÉr/) is a machine consisting of a beam or rigid rod pivoted at a fixed hinge, or fulcrum. A lever is a rigid body capable of rotating on a point on itself. On the basis of the location of fulcrum, load and effort, the lever is divided into three types. It is one of the six simple machines identified by Renaissance scientists. A lever amplifies an input force to provide a greater output force, which is said to provide leverage.
A lever, one of the six simple machines.copyrightCopyright Â© U.S. Department of Transportation, Federal Highway Administration, http://www.fhwa.dot.gov/environment/fspubs/05232810/page16.htm. Students are introduced to three of the six simple machines used by many engineers: lever, pulley, and wheel-and-axle. In general, engineers use the lever to magnify the force applied to an object, the pulley to lift heavy loads over a vertical path, and the wheel-and-axle to magnify the torque applied to an object. The mechanical advantage of these machines helps determine their ability to make work easier or make work faster.