An electronic device dissipating 25 w has a mass of 20 g and a specific heat of 850 j/kg·°c. the device is lightly used, and it is on for 5 min and then off for several hours, during which it cools to the ambient temperature of 25°c. determine the highest possible temperature of the device at the end of the 5-min operating period. what would your answer be if the device were attached to a 0.5-kg aluminum heat sink? assume the device and the heat sink to be nearly isothermal.