[Friday] How to fry a chicken in terms of physics
Even from the school course of physics, we know that energy does not arise by itself and does not disappear into nothing. It can not just create or destroy, you can only convert from one form to another. In this short article I wanted to clarify how to deal with a situation where you have a chicken, no items are available, but you really need to fry this chicken.
On February 14, 2019, in subreddit / r / NoStupidQuestions, the following important question appeared: “If kinetic energy is converted into heat energy, then how much do I need to slap a chicken so that it prepares?”
After 3 days, the answer was found and scientifically substantiated.
')
So, we will convert the kinetic energy of your Kung Fu into the heat energy of a chicken carcass.
For movement with speeds much lower than the speed of light (we do not want to turn the chicken into steam), the kinetic energy of the impact will be
, where m and v are mass and velocity of the arm, respectively. The required amount of heat is calculated by the formula 
. In the calculations we use the following assumptions:
After equating the two energies and performing the calculations, we obtain that one average flop raises the temperature of the chicken by about 0.0089 degrees Celsius. Thus, in order to heat the chicken from 0 to 205 ° C, we will need 23,034 blows.
Well, in order to get a delicious delicacy in one hit, you need to beat at a speed of 1665.65 m / s (3725.95 mph or 5996.34 km / h).
Probably, to perform such a strike, your hand will have to be accelerated on a North American X-15 suborbital rocket plane. But assuming that you want to safely cook the chicken in the indicated way in your kitchen, it would be better to ask Marshal Erickson to slap a billion exploding luminaries on it.
Prehistory
On February 14, 2019, in subreddit / r / NoStupidQuestions, the following important question appeared: “If kinetic energy is converted into heat energy, then how much do I need to slap a chicken so that it prepares?”
After 3 days, the answer was found and scientifically substantiated.
')
A bit of physics
So, we will convert the kinetic energy of your Kung Fu into the heat energy of a chicken carcass.
For movement with speeds much lower than the speed of light (we do not want to turn the chicken into steam), the kinetic energy of the impact will be
, where m and v are mass and velocity of the arm, respectively. The required amount of heat is calculated by the formula . In the calculations we use the following assumptions:- The weight of a human palm is on average 0.4 kg.
- According to the study "THE PHYSICS OF KARATE, 1979" (authors: Michael S. Feld, Ronald E. McNair, Stephen R. Wilk), the average speed of the average slap is determined experimentally - 11 m / s (25 mph).
- Let our chicken weighs 1 kg.
- The specific heat of the bird (laying hens) is 2.72 kJ / kg * ° C.
- Let's assume that the chicken must reach a temperature of 205 ° C in order to be considered cooked, and also that at the very beginning we have frozen chicken with a temperature of 0 ° C.
- To simplify the calculations, we will not take into account that the chicken and the hand consist of water, bones, etc. Also suppose that the collision is absolutely inelastic, that is, the speed of the chicken is zero after the application of kung-fu force to it.
After equating the two energies and performing the calculations, we obtain that one average flop raises the temperature of the chicken by about 0.0089 degrees Celsius. Thus, in order to heat the chicken from 0 to 205 ° C, we will need 23,034 blows.
Well, in order to get a delicious delicacy in one hit, you need to beat at a speed of 1665.65 m / s (3725.95 mph or 5996.34 km / h).
Probably, to perform such a strike, your hand will have to be accelerated on a North American X-15 suborbital rocket plane. But assuming that you want to safely cook the chicken in the indicated way in your kitchen, it would be better to ask Marshal Erickson to slap a billion exploding luminaries on it.
Source: https://habr.com/ru/post/441372/
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