
#1
Nov113, 04:35 PM

P: 18

Let's say that we have a guy who is 6 feet tall and weighs 190 lb. If we were to make him 60 feet tall with the same proportions as before, how much would the man weigh? How much would he weigh if we make him 50 feet tall?




#2
Nov113, 04:39 PM

P: 210

"Same proportions"...
 So he scales the same amount in all 3 dimensions?  So he weighs the same per cubic centimeter as he did before? That might be a good start. 



#3
Nov113, 04:39 PM

HW Helper
P: 775





#4
Nov113, 04:47 PM

P: 18

Scaling problemBoth. 



#5
Nov113, 05:28 PM

Mentor
P: 39,708

And is this question for your schoolwork? 



#6
Nov113, 06:09 PM

P: 18

Nope. Not schoolwork. I'm not in school. I'm just a guy who was curious about this particular question after reading some comics with giant super heroes. Immature I know. But I guess I'll try answering the question. The guys initial volume is 6 cubic feet? His mass is 86 kg. So his density is mass/volume. 8600g/169,901cm cubed. So .5g/1 cm cubed. .5=x/6000 So the sixty foot giant weighs 6,613.8 lbs. 



#7
Nov213, 05:18 AM

P: 754

An alternate approach is to take it one step at a time. You scale the block up by increasing its height by a factor of ten and leaving its width and depth the same. What happens to its weight? Then scale it up by making it ten times larger front to back. What happens to its weight? Then scale it up by making it ten times larger side to site. What happens to its weight? 



#8
Nov213, 07:52 AM

Math
Emeritus
Sci Advisor
Thanks
PF Gold
P: 38,899

Weight and mass of an object with uniform density are proportional to the volume of the object and so scale as the cube of lengths.



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