A meteorological model gives the ground temperature (in ) at a desert site as

MATHEMATICS · Single correct · AP · Calculus AB · Contextual Applications of Differentiation · Contextual Applications of Differentiation

Problem

A meteorological model gives the ground temperature (in

^{\circ}\!\text{C}

) at a desert site as

T(r)=25-2r

, where

r

(in kilometers) is the distance from a heat source. A hiker moves away from the source along a straight path so that

r(t)=3t+4

, where

t

is the time in hours since noon. Determine

\dfrac{dT}{dt}

t=2

hours. (Units:

^{\circ}\!\text{C}\!/\text{h}

) (a)

6

(b)

-3

(c)

-6

(d)

-2