Complete the statement, f( ) = -5.<br><br> Blank 1: <br> Plz answer asap!

Gas is escaping from a spherical balloon at the rate of 12 ft3/hr. At what rate (in feet per hour) is the radius of the balloon

bija089 [108]

Answer:

This is the rate at which the radius of the balloon is changing when the volume is 300 $ft^3$ $\frac{dr}{dt}=-\frac{3}{225^{\frac{2}{3}}\pi ^{\frac{1}{3}}} \:\frac{ft}{h} \approx -0.05537 \:\frac{ft}{h}$

Step-by-step explanation:

Let $r$ be the radius and $V$ the volume.

We know that the gas is escaping from a spherical balloon at the rate of $\frac{dV}{dt}=-12\:\frac{ft^3}{h}$ because the volume is decreasing, and we want to find $\frac{dr}{dt}$

The two variables are related by the equation

$V=\frac{4}{3}\pi r^3$

taking the derivative of the equation, we get

$\frac{d}{dt}V=\frac{d}{dt}(\frac{4}{3}\pi r^3)\\\\\frac{dV}{dt}=\frac{4}{3}\pi (3r^2)\frac{dr}{dt} \\\\\frac{dV}{dt}=4\pi r^2 \frac{dr}{dt}$

With the help of the formula for the volume of a sphere and the information given, we find $r$

$V=\frac{4}{3}\pi r^3\\\\300=\frac{4}{3}\pi r^3\\\\r^3=\frac{225}{\pi }\\\\r=\sqrt[3]{\frac{225}{\pi }}$

Substitute the values we know and solve for $\frac{dr}{dt}$

$\frac{dV}{dt}=4\pi r^2 \frac{dr}{dt}\\\\\frac{dr}{dt}=\frac{\frac{dV}{dt}}{4\pi r^2} \\\\\frac{dr}{dt}=-\frac{12}{4\pi (\sqrt[3]{\frac{225}{\pi }})^2} \\\\\frac{dr}{dt}=-\frac{3}{\pi \left(\sqrt[3]{\frac{225}{\pi }}\right)^2}\\\\\frac{dr}{dt}=-\frac{3}{\pi \frac{225^{\frac{2}{3}}}{\pi ^{\frac{2}{3}}}}\\\\\frac{dr}{dt}=-\frac{3}{225^{\frac{2}{3}}\pi ^{\frac{1}{3}}} \approx -0.05537 \:\frac{ft}{h}$

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On a treasure map, the last clue is that the treasure is buried is buried a certain number of feet away from a tree. the distanc

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3 years ago

Can someone can help me

frozen [14]

Sure with what? u should have asked ur question

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Read 2 more answers

20 POINTS!!! Use the quadratic formula above to solve for h(t) = -4.9t^2 + 8t + 1 where h is the height of the ball in meters an

Elina [12.6K]

Answer:

Two solutions: -0.12 and 1.75.

Step-by-step explanation:

The quadratic formula is:

$\begin{array}{*{20}c} {\frac{{ - b \pm \sqrt {b^2 - 4ac} }}{{2a}}} \end{array}$ . Assuming that the x² term is a, the x term is b, and the constant is c, we can plug the values into the equation.