How long does it take a child on a swing to complete one swing if her center of gravity is 4.00 m below the pivot (length of the pendulum is 4m)? *

earth's neighboring galaxy, the andromeda galaxy, is a distance of 2.54×107 light-years from earth. if the lifetime of a human is taken to be 70.0 years, a spaceship would need to achieve some minimum speed min to deliver a living human being to this galaxy.