The rate at which a body cools also depends on its exposedsurface area S. If S is a constant, then amodification of (2), given in Section 3.1, is
= kS(T ?Tm),
where
k < 0
and Tm is a constant. Suppose that two cupsA and B are filled with coffee at the same time.Initially, the temperature of the coffee is 145° F. The exposedsurface area of the coffee in cup B is twice the surfacearea of the coffee in cup A. After 30 min the temperatureof the coffee in cup A is 95° F. If
Tm = 65° F,
then what is the temperature of the coffee in cup Bafter 30 min? (Round your answer to two decimal places.)
