Question

The radii of Earth and Pluto are 6,371 kilometers and 1,161 kilometers, respectively. Approximately how many spheres the size of Pluto does it take to have the same volume as Earth?
121
154
165
176
189

Answer 1

volume of sphere is equals to 4/3 pi r^3

and let radius of earth be R
and radius of pluto be r

then on dividing4/3 pi R^3
with 4/3 pi r^3

solving it we get...
R^3/r^3

u can get its answer...

give it a try....

Answer 2

The simple approach is to cube the ratio of their radii.

More soophisticated is to reccognize that packing spheres into large volumes typically produces about 50% void volume.

You should ry the simple answer first!

Answer 3

i got 165

Answer 4

Ys, that is (R/r)^3 .

Answer 5

thanks