by Guest » Wed Dec 07, 2016 9:18 pm
This is the example given in the post.................you need to follow the same type of workings
eg. for a 1 x 1 x 1 cube has volume of 1 cu.in then a 2 x 2 x 2 cube has volume of 8 cu.in
As a 2nd example, instead of a cube example we can use a rectangular block.......
eg. for a block with sides 2 in x 3 in x 4 in the volume will be 24 cu.ins and if the larger block has each side 3 times longer then its sides will be 6 x 9 x 12 giving a volume of 648 cu.ins. The ratio of the volumes of the the 2 blocks will be 648 to 24 OR 27 to 1 written as 27:1. But, the ratio of the lengths of the sides was 3 to 1 written 3:1
So for doubling (x2) the sides in the 1st example we had an increase of times 8 in volume
and in the 2nd example for a trebling (x3) of the sides we had an increase of times 27 in volume
2 is the cube root of 8 and 3 is the cube root of 27
So the ratios of the lengths of the sides is the cube root of the ratio of the volumes
So that is all you have to do to find the ratios of the lengths of the sides........you already know the ratio of the two volumes or ratio of weights (because weights are just volumes multiplied by a constant value to convert eg lbs/cu.in......and will cancel in ratio calculations.)