Electromagnetic radiation at temperature t in an enclosure of volume vhas pressure p and energy density u given by и —а т* р 3 1sat" and where a is a constant. (a) write down the ftr and use it to show that as = 4avt2; дт (i) as 4 =-al 3 (ii) ду hint: write e = vu and hence find an expression for de in terms of du and dv; note that uis a function only of t 5 marks] (b) use the results of part (a) to show that the entropy s of the radiation is given by: (i) 4 s = (ii the helmholtz free energy of the radiation is given by f = -pv.

Kiloleter, mega leterhope this !

Ireally just need to get finished with precal! i’m really sorry i have to do this! hope this !

Ohm's law tells you that i = v/r where v is equivalent voltage and r is equivalent resistance of the circuit
since all circuits have the same voltage, your question is really asking which circuit has the lowest total resistance, since the lower the resistance, the higher the current
circuit a has a resistance of 5 ohms; circuit c is in series so has a resistance of 10 ohms; circuit b is in parallel and therefore has a resistance of 2.5 ohms (review your notes on adding resistances in parallel and series); therefore b has the highest current