Abicyclist leaves from her home at 9 a. m. and rides to a
beach40 mi away. because of a breeze off the ocean, thetemperature
at the beach remains 60 of throughout theday. at the
cyclist's home the temperature increases linearlywith time, going
from 60 of at 9 a. m. to 80of by 1 p. m. the
temperature is assumed to varylinearly as a function of position
between the cyclist's home andthe beach. determine the rate of
change of temperatureobserved by the cyclist for the following
conditions: (a) as shepedals 10 mph through a town 10 mi from her
home at 10 a. m.; (b) asshe eats lunch at a rest stop 30 mi from her
home at noon; (c)as she arrives enthusiastically at the beach at 1
p. m., pedaling 20mph.