Use words to describe the relationship between the acceleration of an object and the net force acting on the object

The of a machine determines its "usefulness." a. input force b. output force c. mechanical advantage

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 10.0 m: (a) the initially stationary spelunker is accelerated to a speed of 4.90 m/s; (b) he is then lifted at the constant speed of 4.90 m/s; (c) finally he is decelerated to zero speed. how much work is done on the 68.0 kg rescue by the force lifting him during each stage?

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative