Similar Cylinder

Question

+1

728

2

+134

This one seemed easy at first but I dont think it's worked out how I think it is

I did 10 divided by 5 then squared the answer

then multiplied 18 by the squared answer to find the second area

then took my first answer and cubed it but then i got stuck since neither of the volumes are given

petri Oct 4, 2018

ElectricPavlov · Answer 1 · 2018-10-04T05:28:45

First find the Radius of smaller cylinder:

pi r^2 = area

r = sqrt( area/pi)

r = sqrt(18/pi) = 2.39365 cm

Now calculate the radius of the larger cylinder (using ratios of similarity)

10/5 (r) = 4.787 cm

Volume = area x height

pi (4.787^2)(10) = 720 cm^3

CPhill · Answer 2 · 2018-10-04T05:37:55

The scale factor of B : A = 2 : 1 = 2

Therefore...the area of the cross-section of "B' is Cross-Section of A * scale factor^2 =

18 * 2^2 = 18 * 4 = 72

Therefore....the volume of B = cross-section area of B * height of B = 72 * 10 = 720 cm^3