I don't know how many are familiar with this math club, I think it is mostly a southern thing, but here is a question which remains to stump me.(adsbygoogle = window.adsbygoogle || []).push({});

---------

Wire of 0.1cm is tightly wound (with no gaps in between layers) around a cylindrical pole of 3cm radius between heights of 0cm and 1cm. As a result, this part of the pole thickens, and the new radius is (4+h), where h is the height. How many centimeters of wire were used up?

(Hint: Length * Cross-sectional Area = Volume)

----------------

Ok, here are my few thoughts.

I guess you need to find the volume and the cross-sectional area, and thus divide to find the length.

For volume, an inegral of something along of the lines of [tex]\pi\int_{0}^{1}(4+h)^2dh[/tex] might find the volume.

For cross-sectional area, perhaps (3)(4+h).

Thanks,

Jameson

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Mu Alpha Theta Question

**Physics Forums | Science Articles, Homework Help, Discussion**