In the radioactive decay of U238 the center of the emerging a particle is at a certain instant 9.0×10-15m from the center of the residual nucleus Th234. At this instant what is (a) the force F on the a-particle and (b) what is the acceleration of the a-particle? (Note: an alpha particle is the nucleus of a Helium atom and therefore consists of two protons and two neutrons.)