Physics simplified!

I have no reason at all to want to know these things or have I? Is it time for me to develope an inferiority complex?:D I still say that formula is of little practical use to the average person, to a scientist may be but not us yokels.

It was really just for entertainment, that’s all. The lecturer in the You Tube clip is very smart and knows his beans, but he talks too fast that even most science boffins would have to watch the clip several times over to make head or tail of what he is trying to illustrate. If I was in his class, I would have been completely lost if there wasn’t the means to replay his lecture. 😀

Physics simplified

As Nagoshi is quick to point out, there is a HUGE difference between in game physics and PhysX.

The two words are not interchangeable.

Mike, this has all sorts of uses, how quickly your beer warms up, how fast the roast cools etc….:diablo:

I have no reason at all to want to know these things or have I? Is it time for me to develope an inferiority complex?:D I still say that formula is of little practical use to the average person, to a scientist may be but not us yokels.

convection 😀

Wonderful, and of what practical use is that knowledge to the average person you see every day on the streets of Britain? None as far as I can make out.

Mike, this has all sorts of uses, how quickly your beer warms up, how fast the roast cools etc….:diablo:

With an attitude like that…..it’s a wonder we’re not all living in caves! 😀

Wonderful, and of what practical use is that knowledge to the average person you see every day on the streets of Britain? None as far as I can make out.

From Wikihow (this just about sums it up) :

Newton’s law of cooling is yet another variation of the compound interest law. It states that the time-rate of decrease in body temperature in excess of the temperature of the surrounding air is proportional to the body temperature above that of the surrounding air. Let x = body temperature above that of the surrounding air, t = time, we have dx/dt = kx, where k is a constant. The solution to this differential equation is x = ce^(kt), where c is an arbitrary constant, as above. Suppose this excess temperature, x, was at first 80 degrees, and drops to 70 degrees after a minute. What will it be after 2 minutes?

Let t = time in minutes, x = excess temperature in degrees, we have 80 = ce^(k*0) = c. Also, 70 = ce^(k*1) = 80e^k, so k = ln(7/8). So x = 70e^(ln(7/8)t) is a particular solution to this problem. Now plug in t = 2, we have x = 70e^(ln(7/8)*2) = 53.59 degrees after 2 minutes.

The lecturer owes me! His hits have gone up from 7 to 89, and he has a rating and a comment 😀

:D:D

The lecturer owes me! His hits have gone up from 7 to 89, and he has a rating and a comment 😀

Mpemba effect. http://en.wikipedia.org/wiki/Mpemba_effect

Hot water will make ice-cubes faster than cold water .:) I guess you have a good understanding anyway. 🙂

I have seen this before, but I forget the reason…does anyone know the answer?

I did physics at uni and it brings back memories of the intractable Hungarian-accented English of one of the lecturers in thermodynamics.
The postscript to that is that a few years later I was introduced to a girl in Liverpool who, on discovering my background, persuaded me over a drink or three to deliver an impersonation of the eccentric Hungarian. Only when I’d dug myself right into the hole did she reveal that he was her father:D

:D:D I am glad things like this happen to other people, as digging big holes seems to be my forte.

I did physics at uni and it brings back memories of the intractable Hungarian-accented English of one of the lecturers in thermodynamics.
The postscript to that is that a few years later I was introduced to a girl in Liverpool who, on discovering my background, persuaded me over a drink or three to deliver an impersonation of the eccentric Hungarian. Only when I’d dug myself right into the hole did she reveal that he was her father:D

Hot water will make ice-cubes faster than cold water…

Apparently so, under certain circumstances…..but I haven’t a clue about that one! :confused:

Hot water will make ice-cubes faster than cold water .:) I guess you have a good understanding anyway. 🙂

Excellent point…..assume in this case the room is 20°C warmer than the inside of the fridge…

…unlike my house at the moment where there isn’t much in it! 😡

:D:D

I can use this formula to calculate how fast to drink my wine before it goes out of the “drinkable” temperature range, but I will have to factor in the non-linear (and non continuous function) reduction in quantity. However, I am sure the lecturer will guide us through the calculation with ease; I must say that he certainly appears to be “au fait” with the subject. 😀 (or just keep it in a chiller)

Excellent point…..assume in this case the room is 20°C warmer than the inside of the fridge…

…unlike my house at the moment where there isn’t much in it! 😡

Guess it could also depend on how cold the room was?