Grain is pouring into a silo to be stored for later use. Due to the friction between pieces of grain as they rub against each other during the pouring process, one piece of grain picks up a charge of 6.0 E -10 C, and another piece of grain picks up a charge of 2.3 E -15 C. What is the electric force between them if the pieces of grain are 2 cm apart? Remember to identify all data (givens and unknowns), list equations used, show all your work, and include units and the proper number of significant digits to receive full credit.