What mass must a glass be to burn off the number of calories in a mouthfull of beer by taking a swig?

Question

Using the number of calories per pint of bitter, and the average volume consumed in a mouthful of beer it is possible to calcualte the number of calories in 1 mouthfull of beer. Using the number of energy used by lifting a mass through a height of 0.5m it is possible to calculate the calories burned by taking a swig. As the mass of the glass increases, a point is reached where the action of drinking beer burns off the same number of calories within the mouthfull of beer. Beyond this point, drinking beer is a weight loosing exercise. How heavy must the glass be?

Answer 1

I don't know how to do the math but I had to compliment you on a really kool question.

Answer 2

Remember to take into account that a food calorie is actual a kilocalorie to a chemist.  So there are around 4,000 joules per Calorie in a beer, not 4.  A joule is a kg-m^2/s^2, gravitational potential energy is m*g*h (m = mass, g = 9.8 m/s^2, h = height), so that means for every Calorie in a beer, the glass has to weigh around 825 kg, or about a ton.  I think there is more than one calorie in a good-sized swig of beer.  

If you had your beer on a dumbwaiter and had to haul it up 100 m each time you wanted to drink some, then it would a more manageable 5 kg or so.  Probably it could be half that height since there would be a lot of mechanical losses in the pulley.  

Or you could drink your beer on Jupiter, where g is a lot bigger.  If you walked to Jupiter, that would work off a lot of calories as well.

Edit:  I did this math in my head so it's a little off.  There are around 4.18 joules per calorie, I forget exactly and didn't bother to look it up.  The 5 kg for the 100-m beer lift might actually be closer to 4 kg on reconsidering.

Answer 3

ave energy available from pint of beer=720Kj

So mouthfull*=720/12=60Kj

WD raising pint to mouth=m*g*h+energy wasted as heat=4*m*g*h

>4*m*g*h=60000J..>m=3000Kg ..that's wat I call 'heavy beer'..it's not Millerlite!

*we field tested the mouthfulls in local pub..when we tried to reclaim expenses as it was purely for research purposes, the stupid barstewards threatened us and we were forced 2 leave!