While waiting for the bus you take a seat on the metal bench at the bus stop. The bench feels very cold to you. Why? A. The warmth in your hands is being transferred to the bench via conduction
OB. The warmth in your hands is being transferred to the bench via convection
OC. The coldness of the bench is being transferred to your hands via convection
OD. The coldness of the bench is being transferred to your hands via conduction

On a mild saturday morning while people are working inside, the furnace keeps the temperature inside the building at 23degreesc. at noon the furnace is turned off, and the people go home. the temperature outside is a constant 16degreesc for the rest of the afternoon. if the time constant for the building is 3 hr, when will the temperature inside the building reach 18degreesc? if some windows are left open and the time constant drops to 2 hr, when will the temperature inside reach 18degreesc?