An example of magnetohydrodynamics (mhd) comes from the flow of a river (salty water). this fluid interacts with the earth’s magnetic field to produce a potential difference between the two river banks. how would you go about calculating the potential difference?

First answer marked as brainiest which is the correct equation describing the first law of thermodynamics? a) when the internal energy of a system changes, it equals the amount of heat added plus the work done. b) when work is done by the piston, it is equal to the heat added plus the change in internal energy of the system. c) when heat is added to the system, it is equal to the amount of work done by the piston plus the change in internal energy of the system.