







Le salinon d'Archimèdre 
19990311 

Don Craig pose la question : I am trying to find the English translation of "Le salinon d'Archimèdre" and would appreciate any help. This is a figure, presumably studied by Archimedes, created from 4 semicircles. Since I can't draw it for you, I will try to describe it with the help of the 5 collinear, horizontal points below. . . . . . A B C D E A semicircle is constructed on AE as diameter (let's say above AE). Two more semicircles are then constructed with diameters AB and DE on the same side of the line AE as the first semicircle (above it). Finally, a fourth semicircle is constructed on diameter BD, this time on the opposite side of the line AE from the others (i.e. below the line). These semicircles and the region enclosed by them constitute what is called in French "Le salinon d'Archimèdre". If you know the English name of this curve I would appreciate it if you let me know. Harley Weston lui répond. 





Archimedes, Euclid and "Circular Reasoning" 
20151115 

Ron pose la question : I have read about Archimedes and his work with sphere in cylinder and cone in cylinder and the volume relationships. Did he or any others also extend this to regular based polygon based regular like pillars, and columns? The ratio of 1/3 to 1 whole holds true with all regular based columns as example: a regular pyramid having a regular hexagon base inside a regular hexagon column of equal height. Chris Fisher lui répond. 





Archimedes Burning Mirror 
20120717 

Frakeetta pose la question : Archimedes Burning Mirror
There is a story about Archimedes that he used a “burning mirror” in the shape of a paraboloid of revolution to set fire to enemy ships in the harbor. What would be the equation of the parabola that one would rotate to form the appropriate paraboloid if it were to be designed to set fire to a ship 100m from the mirror? How large would the burning mirror need to be? What is the likelihood that this story is true? Robert Dawson lui répond. 





How much work is done? 
20111015 

Jean pose la question : "A conical buoy that weighs B pounds floats upright in water with its
vertex "a" feet below the surface. A crane on a dock lifts the buoy
until its vertex just clears the surface. How much work is done ?" Penny Nom lui répond. 





Archimedes' formula for parabolic arches 
20090123 

La pose la question : Use calculus to verify Archimedes' formula for y=9x^2. Prove Archimedes' formula for a general parabolic arch. Harley Weston lui répond. 





The perimeter of a regular polygon 
20070918 

Ashwynn pose la question : why does the area of regular polygons with a perimeter of 1000m increase as the number of sides increase? Stephen La Rocque lui répond. 





The volume of a sphere. Why 4/3? 
20050530 

Lauren pose la question : You know when you find the volume of sphere? I know the formula is V= 4/3 pi r^{3} but why do they use 4/3? Penny Nom lui répond. 





Volume of a sphere 
20000521 

Kevin Partridge pose la question : Does anyone have a way to physically demonstrate how to explain the volume formula for a sphere? Or perhaps how to derive the formula without calculus? Harley Weston lui répond. 





A roll of paper 
20000115 

Richard pose la question : I have a roll of paper, wrapped around a corrugate core, whos diameter is 10.750 in. The outer diameter of the roll is approx. 60 in. The thickness of the paper is .014 in. I am trying to find out how much linear feet of paper is left on the roll, given only the diameter of paper remaining on the core. Chris Fisher and Harley Weston lui répond. 





Approximating pi. 
19961104 

Ben Dixon pose la question : How do you calculate Pi? Do you have to somehow combine the equation for a circle with the formula for the circumference? Chris Fisher lui répond. 

