Two identical cells each having e. m.f. 1.5V and internal resistance 0.5ohm are connected in series to a coil of resistance 5ohm. What is a) the effective e. m.f. of the cells?

A10-kg piece of aluminum sits at the bottom of a lake, right next to a 10-kg piece of lead, which is much denser than aluminum. which one has the greater buoyant force on it? explain. b - the aluminum a) both have the same buoyant force. b) the aluminum c) the lead d) it cannot be determined without knowing their volumes.