
#1
Jan2208, 08:03 PM

P: 87

Consider the solid S described below.
The base of S is a circular disk with radius 3r. Parallel crosssections perpendicular to the base are squares. Find the volume V of this solid. I tried this.... A(x) = pi*r^2 = pi*(3r)^2 = pi*9r^2 V(x) = integral from 0 to 3r(pi*9r^2 dx) = pi*27r^3 Am I approaching this problem the wrong way? Thanks for the help! 



#2
Jan2208, 10:53 PM

HW Helper
P: 1,664

So what you need is to find the length of a chord of the circle which has its midpoint at a distance x from the circle's center. That length gives you the area A(x) of each crosssection. You would then integrate A(x) from x = 0 to x = 3r and multiply the resulting volume by 2. 


Register to reply 
Related Discussions  
Hieght of a volume in a cylinder on its side, with known volume.  Precalculus Mathematics Homework  2  
circular disk rotates with student on it  Introductory Physics Homework  4  
Volume of Right Circular Cylinder  Calculus & Beyond Homework  3  
volume expansion problem...wheres initial volume?  Introductory Physics Homework  2  
Disk speed NON UNIFORM and UNIFOR CIRCULAR MOTION  Introductory Physics Homework  3 