Question

im so confused :( Willie Makit blows up a spherical balloon. He recalls that the volume is V=4/3Pi*r^3. In order for the radius to increase at 2cm/sec, how fast must Willie blow air into the balloon when the radius is 3 cm?

Answer 1

given:
r'=2cm/sec
r=3cm
find V'

look at example 1:
http://tutorial.math.lamar.edu/Classes/CalcI/RelatedRates.aspx

Answer 2

i just looked at it and tried to figure it out but i just don't get it. in the example you gave me there was already a rate that the air was being pumped, but in mine there is none. it's asking for the rate. I just don't get it

Answer 3

forget it :) i figured it out! thanks!!!!