Any physics geniuses out there

[DrNunes]

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So I have this one physics problem that is kicking my... you know what. I came up with some answers but am not too sure of them. What do you think?


A rectangular water tank is supported above the ground by four pillars 5.0 m long whose diameters are 20 cm. If the tank were made 10 times longer, wider, and deeper, what diameter pillars would be needed? How much more water would the tank hold?

PS
Please don't be a jerk and tell me something rude.

 

[goldenwest]

So I have this one physics problem that is kicking my... you know what. I came up with some answers but am not too sure of them. What do you think?


A rectangular water tank is supported above the ground by four pillars 5.0 m long whose diameters are 20 cm. If the tank were made 10 times longer, wider, and deeper, what diameter pillars would be needed? How much more water would the tank hold?

PS
Please don't be a jerk and tell me something rude.

Diameter of the pillars doesn't matter assuming you can position them. Think about it. It doesn't matter how wide or tall they are... just where they are placed underneath the tank. (Depending on the material all of this stuff is made out of, but that's not mentioned so you can assume to omit it.) You can figure out the rest on your own.

 

[DrNunes]

Well for this problem the diameter of the pillars are relevant.

 

[goldenwest]

Well for this problem the diameter of the pillars are relevant.

What makes you say that?

 

[DrNunes]

My teacher. Hahaha. And since he is dealing out the grades he is right.
But this is what I got anyways.

Original Pillar
Height 5 m
Diameter 0.2 m
Tank vol. (X)^3

New Pillar
Height 5mx10=50m
Diameter 0.2mx10=2m
Tank vol (X x 10)^3=[(X^3)(1,000)]

 

[vivalavie]

So I have this one physics problem that is kicking my... you know what. I came up with some answers but am not too sure of them. What do you think?


A rectangular water tank is supported above the ground by four pillars 5.0 m long whose diameters are 20 cm. If the tank were made 10 times longer, wider, and deeper, what diameter pillars would be needed? How much more water would the tank hold?

PS
Please don't be a jerk and tell me something rude.

Did you copy the problem exactly? Nothing like "the pillars are at their breaking point" along with a stress/strain thing or Young's modulus? Nothing about keeping the pressure equal? I'm telling you this isn't the whole problem, either you're missing something or your professor is.

 

[DrNunes]

First off I am completely lost, well not completely but you get what I am saying. This is my first class in physics and my book doesn't help with a darn for this problem. The problem was given to use on a worksheet that also sucks ass.

That is the entire problem. Unfortunately. Here is the article that goes with it. I couldn't find anything all that useful in it but maybe you can.

http://www.brookscole.com/physics_d...urces/003026961X_serway/optional/scaling.html

By the way thanks for the replies 🙂

 

[goldenwest]

Well, I guess they are assuming that you can't particularly position the pillars and that their surface area has to increase directly with the surface area of the base of the tank. In this case, the diameter would increase to 2m, the height would not change, and the tank would hold 1000x its volume.

 

[vivalavie]

Well, I guess they are assuming that you can't particularly position the pillars and that their surface area has to increase directly with the surface area of the base of the tank. In this case, the diameter would increase to 2m, the height would not change, and the tank would hold 1000x its volume.

I guess... very poorly worded question. Maybe the professor threw it in to make sure you weren't cheating by using SDN

 

[omgyou8myrice]

Far from a physics genius, but that question makes no sense to me. Is it to be assumed the pillars are currently at their maximum load for that amount of water? If so, just look at the ratio of how much water it held before being made larger to the new amount, and apply that ratio to the pillars. That's really all I can think of.

 

[ILikeDrugs]

What kind of pillars are we talking about? Pillars made of cardboard or pillars made of titanium? Me thinks you are a trollol.

 

[addo]

so we can get help on our hw now?

 

[Geekchick921]

so we can get help on our hw now?

Nope, but even godlike beings like forum moderators need sleep. 😉

Sorry, but as addo said, SDN is not the place for homework help. Thread closed.