What force causes a 1 kg. mass to accelerate at rate of meter per second each second

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

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

Explain vector addition, triangle method and parallelogram method