During a manned mission to mars, astronaut mark watney is presumed dead after a fierce storm and left behind by his crew. but watney has survived and finds himself stranded and alone on the hostile planet. with only meager supplies, he must draw upon his ingenuity, wit and spirit to subsist and find a way to signal to earth that he is alive. if mark watney uses am waves (λ approximately 102 meters) to try and contact nasa, how long, in minutes, will it take for his message to reach earth from mars?

Hjulstrom's diagram plots two curves representing (1) the minimum stream velocity required to erode sediments of varying sizes from the stream bed, and (2) the minimum velocity required to continue to transport sediments of varying sizes. this is a modified version of the diagram, showing only the transport segment. stream competence refers to the heaviest particles a stream can carry. according to hjulstrom's diagram stream competence depends on a) particle size. b) stream velocity. c) stream deposition. d) stream channel shape.