## Density Lab B

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### Re: Density Lab B

UTF-8 U+6211 U+662F wrote:
bobthebuilderman wrote:1. What is the density of each liquid in the jar that:
- has a volume 10 L
- contains equal amounts of Liquid A and Liquid B
- Liquid A weighs 60 grams

2. What is the density of water at 0 degrees C? -50 degrees C? 100 degrees C?
3. What is the population density of country A if it has 545,000 people in 10,000 squared km?
1. Cannot answer without liquid B's mass
2. Ok so water is its most dense at 3.98C, at 1 g/cm^3. So, using water's volumetric temperature expansion coefficient (0.0002 m3/m3 degrees C), water is:
0C - 999.204633112 kg/m^3
-50C - 989.319308743 kg/m^3
-100C - 979.627663118 kg/m^3
3. 545 people per km^2
ope, miscalculated. 54.5*
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UTF-8 U+6211 U+662F
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### Re: Density Lab B

(Just so you guys know, you can use either the [hide],
`, or [spoiler] tags to hide your answers. This prevents spoiling from people who are following the thread.)`

bobthebuilderman
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### Re: Density Lab B

Hey there, its Bob,

Sorry about the lack of info for number 1.
Also, what do you mean by the "volumetric temperature expansion coefficient"?

Thanks,
Bob
yes

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### Re: Density Lab B

bobthebuilderman wrote:Hey there, its Bob,

Sorry about the lack of info for number 1.
Also, what do you mean by the "volumetric temperature expansion coefficient"?

Thanks,
Bob
The volumetric temperature expansion coefficient determines how much an object expands when it is heated.

bobthebuilderman
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### Re: Density Lab B

UTF-8 U+6211 U+662F wrote:
bobthebuilderman wrote:Hey there, its Bob,

Sorry about the lack of info for number 1.
Also, what do you mean by the "volumetric temperature expansion coefficient"?

Thanks,
Bob
The volumetric temperature expansion coefficient determines how much an object expands when it is heated.
I assume the inverse is true when cooled, right?
yes

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### Re: Density Lab B

bobthebuilderman wrote:
UTF-8 U+6211 U+662F wrote:
bobthebuilderman wrote:Hey there, its Bob,

Sorry about the lack of info for number 1.
Also, what do you mean by the "volumetric temperature expansion coefficient"?

Thanks,
Bob
The volumetric temperature expansion coefficient determines how much an object expands when it is heated.
I assume the inverse is true when cooled, right?
Yes, exactly

bobthebuilderman
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### Re: Density Lab B

Hey there, its Bob.

How do I find the maximum possible payload of a balloon filled with any gas in terms of newtons?
How do I find the number of grams in a tank of gas? Assuming STP

Thanks,
A confused Bob
yes

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### Re: Density Lab B

bobthebuilderman wrote:Hey there, its Bob.

How do I find the maximum possible payload of a balloon filled with any gas in terms of newtons?
How do I find the number of grams in a tank of gas? Assuming STP

Thanks,
A confused Bob
Some hints

For the first question, remember that for something to float in a fluid, its density must be smaller than that of the fluid.

For the second question, use the ideal gas law and molar masses.

bobthebuilderman
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### Re: Density Lab B

Bob again,

I hope I'm not annoying anyone here for asking a lot of questions.
Anyways, here's a question:
A hot air balloon with a volume of 500 m3 weighing 50 kg needs to lift a driver weighing 62 kg and
three passengers each weighing 60 kg. Outside air is at 25o C with a density of 1.18 kg / m3.

What is the temperature that the air in the balloon needs to be heated to? (round to the nearest C)
yes

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### Re: Density Lab B

Edit: Oops this is the question marathons ignore this

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