In space, astronauts don’t have gravity to keep them in place. that makes doing even simple tasks difficult. gene cernan was the first astronaut who worked on a task outside a spaceship. he said of the experience, “every time i’d push or turn a valve, it would turn my entire body at zero gravity. i had nothing to hold on to.” as he worked, gene cernan’s heart rate and temperature went so high that his fellow astronauts worried that he wouldn’t survive.

think about routine tasks that astronauts might need to do inside and outside a spaceship. choose several tasks, and describe the features the ship and spacesuits should have to account for zero gravity as the astronaut completes the task. use newton’s laws of motion in your analysis.

An  atom  (ours, not carroll's) consists of a positively charged  nucleus, surrounded by one or more negatively charged particles called  electrons. the positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral. most of an atom's mass is in its nucleus; the mass of an electron is only 1/1836 the mass of the lightest nucleus, that of hydrogen. although the nucleus is heavy, it is quite small compared with the overall size of an atom. the radius of a typical atom is around 0.1 to 0.25 nanometres (nm), whereas the radius of a nucleus is about 10-6  nm.  *  if an atom were enlarged to the size of the earth, its nucleus would be only 200 feet in diameter and could easily rest inside a small football stadium.read more on -