Alever with an input arm of 2 meters high has a mechanical advantage of 4 what is the output arm's length

Acave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. the lift is performed in three stages, each requiring a vertical distance of 11.0 m: (a) the initially stationary spelunker is accelerated to a speed of 4.80 m/s; (b) he is then lifted at the constant speed of 4.80 m/s; (c) finally he is decelerated to zero speed. how much work is done on the 78.0 kg rescue by the force lifting him during each stage

Ais useful when you need a simple machine to you separate two things. a. lever b. screw c. pulley d. wedge

Acompound machine is also called a machine. a. force b. simple c. complex d. directional