Saturday

August 30, 2014

August 30, 2014

Posted by **Branden** on Friday, August 26, 2011 at 1:27pm.

And

The radius of a circle is decreasing at a rate of 2 ft/minute. Find the rate at which the area is decreasing with respect to time when the radius is 4 feet?

- Calculus -
**Reiny**, Friday, August 26, 2011 at 2:11pmV = (4/3)πr^3

dV/dt = 4πr^2 dr/dt

given dV/dt = 10 ft^3/min

so at r = 4

10 = 4π(16) dr/dt

dr/dt = 10/(64π) or appr. .05 ft/min

If A = 4πr^2, do the second question the same way.

**Related Questions**

Calculus - A spherical party balloon is being inflated with helium pumped in at ...

math-calculus - A spherical party balloon is being inflated with helium pumped ...

Calculus - a spherical balloon is inflated with gas at the rate of 500 cubic ...

calculus - A spherical balloon is being inflated at a rate of 10 cubic inches ...

Calculus - A spherical balloon is being inflated at a rate of 10 cubic inches ...

Calculus - Air is being pumped into a spherical balloon and the volume is ...

calculus - A spherical balloon is leaking air at 2 cubic inches per hour. How ...

calculus - gas is pumped into a spherical balloon at the rate of 1 cubic feet ...

calculus - a spherical balloon filled with gas has a leak that permits the gas ...

relaited rates - A spherical balloon is being inflated so that its volume is ...