# Finding rate of change of volume in a cylinder.

• Nov 20th 2011, 01:58 PM
stefanhinote
Finding rate of change of volume in a cylinder.
I've attached a picture to make things easier to read.

Attachment 22819
The rate I got sounds absurd, and it doesn't take the "3 seconds" into consideration.

Did I do something wrong? Any help would be greatly appreciated.
• Nov 20th 2011, 02:36 PM
skeeter
Re: Finding rate of change of volume in a cylinder.
your calculation of dV/dt is correct, except for your units ... the time does not matter since dV/dt = k(dh/dt)
• Nov 20th 2011, 02:44 PM
stefanhinote
Re: Finding rate of change of volume in a cylinder.
Quote:

Originally Posted by skeeter
your calculation of dV/dt is correct, except for your units ... the time does not matter since dV/dt = k(dh/dt)

mm^3 / sec since it's volume, my bad. :)

Thank you!
• Nov 20th 2011, 02:46 PM
SpringFan25
Re: Finding rate of change of volume in a cylinder.
your answer is fine except that the units are $mm^3 / sec$

im not sure why 3 seconds is mentioned in the question to be honest, as ther ate of change will be constant provided the candy continues to move at 7mm/sec.

edit: i was too slow :P
• Nov 20th 2011, 02:47 PM
stefanhinote
Re: Finding rate of change of volume in a cylinder.
Quote:

Originally Posted by SpringFan25
your answer is fine except that the units are $mm^3 / sec$

im not sure why 3 seconds is mentioned in the question to be honest, as ther ate of change will be constant provided the candy continues to move at 7mm/sec.

I wondered the same, I guess it's just added to "throw off" people. :p