Physics question

[farmpond1]

Johhny has a 1/48 scale model F-15 airplane made of gold (Johnny is very rich).  The model weighs about 25 lbs.  Why is it that a full scale, real F-15 (48 times bigger than the model and made of lightweight materials) weighs approximately 31,000 lbs and not 1,200 lbs?  Or, to put it differently, if you shrunk down a F-15 to 1/48th of it's original size, why wouldn't it weigh a healthy 645.833 lbs?

[Pitchinkid]

lol man i have no clue, i feel more dumb than usual now.

[farmpond1]

lol man i have no clue, i feel more dumb than usual now.

This sort of thing keeps me up at night.

[tyrius.]

Johhny has a 1/48 scale model F-15 airplane made of gold (Johnny is very rich). The model weighs about 25 lbs.

How do you know this is true?

[Still a Bigbuckifan]

I think you need to look at the law of exponential growth. If you double the size of the model you don't double the weight the weight grows exponentially.   Hope this helps.

[Pitchinkid]

yep, you lost me, i know i can catch fish on a jig, thats it.lol ;D

[farmpond1]

Johhny has a 1/48 scale model F-15 airplane made of gold (Johnny is very rich). The model weighs about 25 lbs.

How do you know this is true?

I don't.  It's just an approximation (I wish I had a solid gold model F-15 so I could find out).   But even if it weighed half or twice as much, the question would remain about the same).

[atx_newbie]

Well because F-15's are made out of aluminum, not gold.  Image how much heavier a gold beer can would be.  Also, model scales represent the lengths, heights, and widths, not weights.

[farmpond1]

yep, you lost me, i know i can catch fish on a jig, thats it.lol ;D

Well, you're doing better than me.  I'm not very good with jigs.  Not patient enough, I think.

[tyrius.]

Johhny has a 1/48 scale model F-15 airplane made of gold (Johnny is very rich). The model weighs about 25 lbs.

How do you know this is true?

I don't. It's just an approximation (I wish I had a solid gold model F-15 so I could find out). But even if it weighed half or twice as much, the question would remain about the same).

I think the difficulty in figuring this out is in the fact that the approxiamation is GROSSLY incorrect.  A gold bar that is 7" X 3 5/8" X 1 3/4" weighs 27.5 pounds.  A 1/48th model is bigger than that.

Also, a 1/48th model is 1/48 of the length, 1/48th of the width, and 1/48th of the height.  You can't just take the weight divided by 1/48th as that only takes into account one dimension out of three.  The true scaled down weight of 31,000 lbs would be about 0.28 pounds.  31000/48/48/48.

[Pitchinkid]

im sorry that is incorrect you forgot to say your answer in the form of a question lol j/k looks good to me

[fourbizz]

A simple way to look at it:

It is 1/48 of real life in EXTERNAL DIMENSIONS. Meaning that if a F/18 had a 48 ft wingspan, a 1/48 model would have a 1 ft wingspan.

It is NOT 1/48 of an F/18's VOLUME, which would be neccesary when figuring out "how much gold it is made of".

[Low_Budget_Hooker]

less fuel

[frogtog]

All of my important questions will be directed to Tyrius from now on. ;D

[CFFF 1.5]

Part of what LBH said is true. But you have to think of all the other stuff in the plane. Engine, all the wires in the plane that the model doesn't have deats controls, all add to the weight of the actual plane, none of which is in the model.