A silo has a cylindrical main section and a hemispherical roof. If the height of the main sectio is 10m, what should the radius be in order that the volume of the silo(including the part inside the roof section) is 2000 m cube.?
2. The height, length, and width of a small box are consecutive integers with the height being the smallest of the three dimensions. If the length and width are increased by 1 cm each and the height is doubled, then the volume is increased by 120cm cube. Find the dimensions of the original small box.
2007-10-02 14:40:34 · 1 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
V=pi*r^2*10 +2/3 pi*r^3=2000
2/3*pi*r^3+10*pi*r^2-2000=0 r= 6.6425 m (using a scientific calculator)
2) V = (n-1)n(n+1)
V+120 =2(n-1) (n+1) (n+2)
120= (n-1)(n+1)(2n+4-n) = (n^2-1)(n+4)
120=n^3+4n^2-n-4 so n= 4
and the dimension are 3,4 and5
2007-10-02 15:32:35 · answer #1 · answered by santmann2002 7 · 0⤊ 0⤋