What is the gain of potential energy of the barbell when it is lifted to this height?

Copper has free electrons per cubic meter. a 71.0-cm length of 12-gauge copper wire that is 2.05 mm in diameter carries 4.85 a of current. (a) how much time does it take for an electron to travel the length of the wire? (b) repeat part (a) for 6-gauge copper wire (diameter 4.12 mm) of the same length that carries the same current. (c) generally speaking, how does changing the diameter of a wire that carries a given amount of current affect the drift velocity of the electrons in the wire?

Which process is represented by the pv diagram? a. the isobaric process b. the isovolumetric process c. the isothermal process d. the adiabatic process

1kg of water needs to recieve 4200j of energy to go from 90 degrees to 91 degrees. what is the specific heat capacity of water? what are the units?