Two particles with charges +7e and -6e are initially very far apart (effectively an infinite distance apart). they are then fixed at positions that are 7.50 x 10^-12 m apart. what is epefinal - epeinitial, which is the change in the electric potential energy?

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.)