Three objects of the same mass begin their motion at the same height. One object falls straight down, one slides down a low-friction inclined plane, and one swings in a circular arc on the end of a string. All three objects end at the same height. In which case does the object have the biggest total work done on it by all forces during its motion?
A. Free Fall
B. Incline
C. String
D. Same

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?