A14.8-g piece of styrofoam carries a net charge of -0.742 µc and is suspended in equilibrium above the center of a large, horizontal sheet of plastic that has a uniform charge density on its surface. what is the charge per unit area on the plastic sheet?

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.