Recent content by chris_usyd

thanks very much, simon. it helps.

anyone knows the difference between a snug tight and a fully tensioned bolt? thanks in advance:thumbs:

by the way, jay, "what are the assumptions in calculating EI that may not be strictly true??" i can't even find one you know, by deflection, i plotted the mid-span moment(M) against the curvature(K). because M=EIk, the slope is the value of EI. i think it is perfect..

but i got different values.. so also need some comparisons.

units? yeah, i am confused as well. isnt N.mm^2? since E(N/mm^2) I(mm^4) the experiment is to examining the stiffness of a steel beam through 2 types of deformation-deflection and curvature.. now i am writing the discussion part, but not many things to be mentioned.

Homework Statement simply put, i got 2.1E+10 N.mm^5 for my steel beam experiment? but i am wonder, what conclusions can i make? 2. The attempt at a solution from online resouce, flexural rigidity is defined as the force couple required to bend a rigid structure to a unit curvature. so ...

thanks Tim, in part a) of this question, i found the semi-axes of this elliptic paraboloid are b*sqrt((h-z)/h) and a*sqrt((h-z)/h) therefore the intersection of the ellipse at height z is going to be [a*sqrt((h-z)/h)]*[b*sqrt((h-z)/h) ]*pi, isn't? which is just pi*(h-z)/h*a*b. then how am i...

thanks :)) sharks

oh about the r drdθ.. that is deltA=r drdθ..

: (( i am confused as well, but this is what is written in my textbook-'course notes for Math2061", University of Sydney, school of mathematics and statistics. basically i think it is just using double integral to find the volume... Tim, does that make sense?

OK.Tim, this is what i learn from my textbook. If f(x,y)>=0 for all (x,y) in some region R, then z= f(x,y) represents a surface sitting above the xy-plane and over R. the double integral f(x,y) dxdy can then be interpreted as the colume of the solid under the surface z=f(x,y),over R, since the...

ok... i do this question like this.. tell me if i am right or not. : )) let x = r∙cos(θ),y = r∙sin(θ) dS = dxdy = r drdθ because x² + y² ≤ b² =>r²∙cos²(θ) + r²∙sin²(θ) ≤ b²=>r² ≤ b² and r is the distance to the origin, which can not be negative. So the range of integration in radial direction...

Homework Statement a elliptic paraboloid is x^2/a^2+y^2/b^2<=(h-z)/h, 0<=z<=h. Its apex occurs at the point (0,0,h). Suppose a>=b. Calculate the volume of that part of the paraboloid that lies above the disc x^2+y^2<=b^2.:confused: 2. The attempt at a solution We normally do the...

how can i set up x and y in polar coordinates?? we usually get a cylinder or whatever the intersection is a circle. in these cases, x=rcos(),y=rsin()...

Tim, same equation for the solid elliptic paraboloid, x^2/a^2+y^2/b^2<=(h-z)/h, 0<=z<=h. the question is : suppose a>=b, calculate the volume of that part of the paraboloid that lies above the disc x^2+y^2<=b^2.( use a suitable integral in polar coordinates.)