How much heat flows per second through a well lagged bar of alummium of thermal cond7ctivity 230W ,the bar has length of 300mm and a cross sectional area of 100 mm² with a temorature difference of 40°c between the ends of the bar

The temperature in gavin's oven is a sinusoidal function of time. gavin sets his oven so that it has a maximum temperature of 280°f and a minimum temperature of 240°. once the temperature hits 280°, it takes 20 minutes before it is 280° again. gavin's cake needs to be in the oven for 30 minutes at temperatures at or above 270°. he puts the cake into the oven when it is at 260° and rising. how long will gavin need to leave the cake in the oven? (round your answer to the nearest minute.)