Final answer:
The laptop battery moves 0.70 C of charge each second, and the electric potential energy increases by 7.56 J per second as this charge moves through the battery with an emf of 10.8 V.
Step-by-step explanation:
Understanding Laptop Battery Charge and Electric Potential Energy
To answer the first part of your question: (a) how much charge moves through the battery each second? We use the relationship between current and charge, which is I = Q/t, where I is the current in amperes, Q is the charge in coulombs, and t is the time in seconds. Given that the laptop uses a current of 0.70 A, we calculate the charge per second (which in this case, time t is 1 second) as Q = I * t = 0.70 C/s.
For the second part: (b) by how much does the electric potential energy of this charge increase as it moves through the battery? The electric potential energy change (ΔU) is given by ΔU = Q * emf, where emf is the electromotive force. With an emf of 10.8 V and a charge Q of 0.70 C passing through each second, the increase in electric potential energy is ΔU = 0.70 C * 10.8 V = 7.56 J per second.