Mathematics

Mathematics

Problem

The radius rr (in meters) of an inflating spherical balloon after tt seconds is modeled by r(t)=0.10 t3/2,t≥0.r(t)=0.10\,t^{3/2},\qquad t\ge0. The volume VV (in cubic meters) of the balloon satisfies V(t)=43πr(t)3V(t)=\frac{4}{3}\pi r(t)^{3}. (a) Express VV explicitly as a function of tt. (b) Determine V′(t)V'(t). (c) Evaluate V′(9)V'(9), including correct units. (d) Interpret the value found in part (c) in the context of the balloon’s inflation. (e) Using your result from part (c), estimate the additional volume of air, in cubic meters, that enters the balloon between t=9t=9 seconds and t=9.1t=9.1 seconds. Justify your approximation.

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