Arod of length 1.2 m has non uniform linear mass density rho_li(x) in kilograms per meter given by rho_l(x) = a + bx^3, where x is the distance in meters from the left end of the rod. (a)what are the si units of a and b? (b) find the total mass of the rod if a = 2 and b = +5. (c)find the position of center of mass of the rod.

(a) calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 10.0 g. silver has 47 electrons per atom, and its molar mass is 107.87 g/mol. (b) imagine adding electrons to the pin until the negative charge has the very large value 1.00 mc. how many electrons are added for every 109 electrons already present