What is the mathmatical formula for finding the surface area of a tube
given its diamator and length?

Hi fred777-ga,

Thank you for your question. Welcome to the wonderful world of
mathematics! I have found the answer to your question :

The surface area of a tube (cylinder) is the product of its
circumference (perimeter) and length.

The formula is :

[pi] 2r h

OR

[pi] d h

...where [pi] is the the constant for circles (3.142 rounded), r is
the radius, d is the diameter (2r) and h is the length, or height, of
the tube.

In other words, the surface area of a tube is :

3.142 X diameter X length


For more information, please do visit this excellent website :

Eric Weisstein's World of Mathematics
http://mathworld.wolfram.com

Circumference
http://mathworld.wolfram.com/Circumference.html

Surface Area
http://mathworld.wolfram.com/SurfaceArea.html



Google Search Terms :

tube surface area
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=tube+surface+area


Hope that answers your question! Please ask for clarification if you
need any.


Have fun,

kyrie26-ga

think of your cylinder as a rolled plane (or a rolled sheet of paper)
and the calculation of its surface can be seen as the product of the
length of that plane (the length of the tube) and its width, which is
equivalent to the circumference of the circle, (pi)x(d).

There is a small amount of confusion in the answers here, although
both correctly answer the question as it was asked.

The surface area of a tube is, as stated, (pi)x(2)x(radius)x(height).

However, both answers mention a cylinder which is a solid object
(unlike a tube which is hollow) and the surface area must include the
'top' and 'bottom' circles. The surface area of one of these circles
is (pi)x(radius)x(radius), therefore both of them are
2x(pi)x(radius)x(radius).

The total surface area of a cylinder is
(pi)x(2)x(radius)x(height)+(2)x(pi)x(radius)x(radius).

Simplifying this (and it does need symplifying!), we have:

surface area = 2r(pi)(h+r) [r=radius, pi=3.141, h=height].

Hopefully this doesn't confuse too much.

I got curious about this and looked it up. It appears that cylinder
and tube can be used interchangably in mathematics to mean a hollow
shape without the ends closed :

Cylinder -- from MathWorld
http://mathworld.wolfram.com/Cylinder.html

"In common usage, the term "cylinder" refers to a solid of circular
cross section in which the centers of the circles all lie on a single
line (i.e., a right circular cylinder). In mathematical usage,
"cylinder" is commonly taken to refer to only the lateral sides of
this solid, excluding the top and bottom caps."

... so that should bury any confusion whatsoever.


Cheers!

kyrie26-ga

A tube has an inside surface and a outside surface and a top and
bottom surface.
Just look at any tube to verfy this.
Surface Area of a Tube = area of outside cylinder + area of inside
cylinder + the area of both ends.
Area of outside of tube = Pi ( outside diameter) X (length)
Area of inside of tube  = Pi (inside diameter) X (length)
Area of 2 ends = 
 2[(Pi)(1/2 outside daimeter) X (1/2 outside diameter) -
   (Pi)(1/2 inside diameter) X (1/2 inside diameter)]