SCIENCE! (questions and answers)

I

IronDuke

Ancient Mariner
Okie dokie, you fancy scienticians. It's time to make yourselves useful.
I'm sure I'm not the only liberal arts major out here who has some questions on every day science, which you guys and gals miht be able to answer. (If you'll be so kind!)

I'll start with this one:
If I drink 1L of water at 4.5 C, how many calories will I have used heating it to body temperature (36.8 C) a few hours later? (I know, calories aren't SI units, but as a Canadian I grew up using a godawful mix of metric and imperial measurements. I think there's 4.18 kJ in a calorie)
 
What kind of dick?

This one?
philip_dick_1.jpg


Or that one?
afish.jpg




:innocent:
 
32.3 calories would be the "obvious" answer but I just know there's bound to be some sort of catch :P
 
Correct me if I'm wrong, but I tried solving this problem using the following formula:

ΔH = mΔt°Cp,

where ΔH is the enthalpy, m is mass in grams, Δt° is the change in temperature, and Cp is the specific heat capacity.
The Cp of water is 4.18J/gK right? Which makes the enthalpy be 1000g x 32.3° x 4.18 J/gK which equals 135014 J which is then 32300 cal since 1 cal=4.18J.

So, in other words, you used 32.3 kcal (I think).
 
Natalie said:
Correct me if I'm wrong, but I tried solving this problem using the following formula...
Click to expand...
I just used the logic that I learned from watching "Supersize Me", that one calorie is the amount of energy required to raise the temperature of one litre of water by one degree celcius.  Looks like we both got the same answer anyway :p
 
the term "calorie" is often used in place of kilo-calorie when describing food and digestion. Why? Probably because people are lazy. But technically, Conor was right in using the term.
 
Here's one for you:

An ice-cube is in a glass of water.  When the ice-cube melts, does the water level rise, fall or stay the same?  Explain.

(This one my physics teacher asked the class and I was the only one to get it right :D  Not to blow my own trumpet or anything :P)
 
Conor said:
Here's one for you:

An ice-cube is in a glass of water.  When the ice-cube melts, does the water level rise, fall or stay the same?  Explain.

(This one my physics teacher asked the class and I was the only one to get it right :D  Not to blow my own trumpet or anything :P)
Click to expand...

It should fall :) If I'm not wrong, it's a matter of mulecular dispositions, and water should be the only fluid to have its volume decreased passing from solid to liquid state.
 
It's bviously been a long time since I've done this kinda thing, but my layman's theory is that the water level would rise.
Something like 10% of an iceburg sticks out of the water, and thus that amount doesn't contribute to the overall volume of the water (the 90% underwater does, though). When it melts, that extra 10% is added to the water's volume, hence you get a rise.
Unless, of course, the density of ice happens to be less than water by exactly that amount (and the more I think about it, the more I realise that it probably is. DOH!)

So, through my above deduction, the water level would probably stay the same! Logic is our friend!
 
Duke, could your question be something that does not involve mathematics for the sake of those who are numerically challenged?
 
That's what we have the trivia thread for, my Mongolian friend.
This thread is for people with real curiosities about everyday science. I asked a question to which I didn't know the answer, and someone answered it for me.
 
This thread shouldn't be called science in that case, it should be called physics, or chemistry or natural science :smartarse: Not all sciences use maths and strange formulae in order to come up with an answer. Give me something of the social sciences so that I won't feel so stupid :D
 
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