2 items are filed under this topic.








The volume of a test tube 
20100520 

From Nick: A maths question. I have a test tube (basically a cylinder but with a rounded
bottom end) and the measurements are: the diameter or width of the tube is
31mm and the total length of the whole tube is 204mm. The question is:
(a) what's the volume of this test tube (rounded to the nearest cubic mm) and
(b) what's the capacity of this test tube (rounded to the nearest mL).
I need to show the full mathematical workings out of the two, not just the
answer. The problem is the circular bottom end of the tube, it isn't flat, that
would make it rather "easy"or straightforward but this is a halfcircle
(like all test tubes are)!! Answered by Penny Nom. 





Measurements on a test tube 
20071030 

From Bruce: I figure that the surface area (SA) of a round bottom test tube
can be determined by the equation SA = 2pi*h*r
where r is the radius of the hemispheric bottom & column part, and
h is the height (h) at any point upwards from the bottommost portion
in the center of the tube.
I haven't been able to come up with an equation yet for the circumference
of such a test tube at any point upwards along the tube based
on the height in its center or on the distance along the outside
of the tube. Answered by Harley Weston. 


