Hot air balloon (1 Viewer)

[davidbarnes]

A hot air ballon by law is requried to have a minimum air capacity of 1000M^3. So whats the smallest one can be (e.g 2 metres high, 3 metres wide etc). I can't seem to work it out. Thanks

 

[davidbarnes]

?

 

[PrettyVacant]

It's like a sphere shaped thing right?

SO just substitute the volume into the formula:

4/3 pi R^3 = V

So that's:

4/3 pi R^3 = 1000m^3
(just find R)
R=1000m/4/3 pi

:\ Hmm?

Don't have a calculator nearby, sorry...

But yeah...

 

[Lucid Scintilla]

It's like a sphere shaped thing right?

SO just substitute the volume into the formula:

4/3 pi R^3 = V

So that's:

4/3 pi R^3 = 1000m^3
(just find R)
R=1000m/4/3 pi

:\ Hmm?

Don't have a calculator nearby, sorry...

But yeah...

MMMMM...not quite, as chousta says.

its not a sphere shape, its oval thus your formula doesnt work. This question can be solved using simple maths max/min but the formula of an oval needs to be used. Ps. this doesnt really seem to be a physics questions(unless there is more to it), its more of a maths question

Hey chousta. How's the Ruse papers? I'll try to find you more, friend.

The volume of an ellipsoid of equation: x²/a² + y²/b² + z²/c² = 1 is 4pabc/3.
This formula is a good approximation for other egg-shaped ovals which are nearly elliptical: 2a is the diameter (i.e. the largest width), 2b is the largest width for a direction perpendicular to the diameter and 2c is the width in the direction perpendicular to both previous directions. Each such width is measured between two parallel planes perpendicular to the direction being considered.


Try working it out now, davidbarnes. Hope that helps.


The / is obviously a obelus (div. sign).

 

[davidbarnes]

Ok, I've not saw that formula before, although will give it a go. Its not a homework question or anything.

I did however find an excellent freeware program called "model hot air balloons", which can do all this + more than what I wanted.

 

[xiao1985]

lol you nerd lucid!!!

i didn't expect any high schoolers to know the formula for eliptoid (sp?)...

@david barnes: but what do you mean by smallest?!

smallest would have the volume of 1000m^3...

 

[watatank]

.....Is a question like this part of the Physics syllabus or a pure interest?

 

[Lucid Scintilla]

Ok, I've not saw that formula before, although will give it a go. Its not a homework question or anything.

KEKEKE, it might work.

I did however find an excellent freeware program called "model hot air balloons", which can do all this + more than what I wanted.

But you can't use it in the exam, so it's probably good to learn it, too, david barnes.

lol you nerd lucid!!!

i didn't expect any high schoolers to know the formula for eliptoid (sp?)...

@david barnes: but what do you mean by smallest?!

smallest would have the volume of 1000m^3...

Kekeke... though I'm still in need of wonderful you and your wonderful assistance, xiao!
Thanks.

I'm a high-schooler? Oh yeah... that's right... now how'd I learn of that formula, eh?^_^
I wanna be a nerd/one who exhibits the qualities of a nerd, but I don't have the motivation, nor effort.

Ellipsoid, Ducky!

.....Is a question like this part of the Physics syllabus or a pure interest?

I'm fairly sure that this would be part of the latter section of the syllabus, if even at all in it.

Dunno... maybe someone can inform us.

Edit:

A hot air ballon by law is requried to have a minimum air capacity of 1000M^3. So whats the smallest one can be (e.g 2 metres high, 3 metres wide etc). I can't seem to work it out. Thanks

???
Well, ... uh, I dunno ... I'm too busy/tired.