Tuesday

September 16, 2014

September 16, 2014

Posted by **Eli** on Tuesday, October 18, 2011 at 3:01pm.

- calculus -
**Steve**, Tuesday, October 18, 2011 at 3:41pmdV/dt = kA.

V = (4/3) π r^3 and A = 4 π r^2

dV/dt = d/dt((4/3) π r^3) = (4/3) π 3 r^2 (dr/dt)

Now let's plug that into the first equation:

(4/3) π 3 r^2 (dr/dt) = k A = k(4 π r^2) = 4 π k r^2

So when we simplify by dividing left and right sides by 4 π r^2, we get:

dr/dt = k

which is saying exactly what we wanted to prove: that dr/dt is constant.

- calculus -
**amy**, Saturday, May 19, 2012 at 8:06pmSteve you are so smart. thank you. you don't how much it helped me. you save my life from this MMAD MATH INSTRUCTOR

**Answer this Question**

**Related Questions**

calculus - A snowball has a radius of 3 inches. Assume the rate with which the ...

Calculus - A snowball has a radius of 3 inches. Assume the rate with which the ...

Calculus - A certain calculus student hit Mrs. Evans in the head with a snowball...

Calculus 1 - A spherical snowball melts in such a way that its surface area ...

calc - The sun is shining and a spherical snowball of volume 210 ft3 is melting ...

calculus - if a snowball melts so that its surface area decreases at a rate f ...

Calculus - A spherical snowball is melting so that its diameter is decreasing at...

calculus - if a snowball melts so that its surface area decreases at a rate of 1...

calculus - If a snowball melts so that its surface area decreases at a rate of 3...

Calculus - If a snowball melts so that its surface area decreases at a rate of 4...