You keep your coffee in a sealable thermal mug which has thermal conductivity k-0.036 W/m k. The mug is about 15 cm high and its average radius is about 3.0 cm and has wall thickness of 5.0 mm. The coffee can be considered to have the same properties of water. If the mug is filled with coffee and placed in room temperature (25 C), Starting from boiling temperature, how long (in minutes) will it take the coffee to cool down to: