If the thermal energy of the system increases by 400 j and 1100 j of heat were added to the system, how much work did the system do

The equation used here is ΔU=Q-W,

where, ΔU is the change in the system's internal energy, Q is the energy transferred to or from the system by  heat, and W is the energy transferred to or from the system by work.

Known:

ΔU=400J

Q=1100 J

W=?

Plug into the equation:

400=1100-W

Therefore W=700 J.

So the system did 700 J of work.

v=ir = 3x15 =45 v

probably not the "magnets"in the magnet, so to speak, are thought to be electrons orbiting in shells. vurrent loops two sides to the loop