PLEASE PLEASE PLEASE HELP Calculate how long a de-orbit burn must last in seconds to achieve the Orion MPCV's change in altitude from 406.1 kilometers to 96.5 kilometers at perigee. Use the equations and conversions provided to find the required burn time.

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.)