Calculate humanoid weight after scaling?

[JQP]

Say you take a 6' 200 lb man and scale him down to 90% of his normal size - what's the formula for calculating his weight if his density remains constant?

 

[JVisgaitis]

180 lbs. Just take 90% of his weight.

 

[Nightfall]

And stuff it in a cake!

 

[JQP]

180 lbs. Just take 90% of his weight.

I could do that, but I don't think it'd be right.

That way my guy would weigh 100 lbs. at 3ft tall, and 400 lbs. at 12 feet tall. The relationship isn't proportional, if memory serves.

 

[Nightfall]

I still say stuff it in a cake.

 

[LightPhoenix]

180 lbs. Just take 90% of his weight.

Actually, by that metric, you'd want 10%, or 20lbs.

BUT,

You may have a relative height, weight, and depth reduction of 90% each way, but that actually reduces volume to 10%*10%*10%, or 0.1%. So, density staying the same, and therefore since weight (by mass) is proportional to volume, the actual weight would be [EDIT Ugh Math] 0.1% of 200lbs, or 0.2 lbs.

 

[Nightfall]

I guess no one wants a cake stuff with guts huh?

 

[JQP]

Actually, by that metric, you'd want 10%, or 20lbs.

BUT,

You may have a relative height, weight, and depth reduction of 90% each way, but that actually reduces volume to 10%*10%*10%, or 0.1%. So, density staying the same, and therefore since weight (by mass) is proportional to volume, the actual weight would be [EDIT Ugh Math] 0.1% of 200lbs, or 0.2 lbs.

Yeah, if you take a cube of 1x1x1 filled with water, and cut any one dimension to 0.5, you now have half as much water in the cube. So what's the formula? Math isn't my strong suit obviously.

Is it

A=B( X * Y * Z)
where

A=new weight
B=original weight
X=new dimensional scale
Y=new dimensional scale
Z=new dimensional scale
?

I think that's it. Order doesn't matter, right? So that's:
A=BXYZ

Formula for cake-filling:
B-A=C
C=Cake filling.

 

[Nightfall]

Uhm okay how about a small man made of cake?

 

[JVisgaitis]

A=B( X * Y * Z)
where

A=new weight
B=original weight
X=new dimensional scale
Y=new dimensional scale
Z=new dimensional scale
?

Holy crap dude! I'm an artist, you trying to kill me? For me, I'd just take the percentage. Do you guys actually calculate real weights? If so, what are you going to do for equipment?