From the Three Stooges' Cookbook

Earlier this week, my cousin Autumn shared a Reddit post that sounded like a perfect topic for me!

There are varying levels of complexity we could go into here:

• The question seems to imply a single slap, but that would be a problem, since it would deliver all the energy to a hand-sized spot. I imagine the sudden release of steam from the chicken would explode bits all over you, so let's forget that.
• Normally the chicken would be cooked in an oven, where the air is held at a fixed temperature, and that energy is transferred to the chicken over time. In this case, we're (presumably) slapping the chicken at room temperature, so we could consider the heat that would be lost to the air, but we're already making assumptions about the energy we're putting into the chicken, so let's forget that.
• From a physics perspective, your hand isn't too different from the chicken, so if you cook one, the other will be just as hot. This is really just a thought experiment though (I hope), so let's forget that.

The first thing we need to figure out is how much kinetic energy is in a slap. Kinetic energy is defined as

According to this Air Force Systems Command document, the mass of a hand is around 426 grams (shockingly provided in metric). For velocity, I don't think anyone has tested the maximum slapping speed, but I figure it's similar to pitching a baseball, which has a record of 105.1 mph. Putting those together, we get about 470 Joules.

Now we need to know how much heat it takes to cook the chicken. We want to bring it from a refrigerated 40°F to a safe cooking temperature of 165°F. To convert between temperature and energy, we use the specific heat, which has been tabulated for chicken as 2.72 kJ/kg °C. If we have a 3 pound (1.36 kg) chicken, the energy we need is 191 kJ.

Putting that together with the energy in a slap, it will take 406 slaps to cook the chicken! You might be thinking that's doable, but those are 406 record-breaking fastball slaps. Then there are all the issues we set aside at the beginning, including the fact that if ALL the energy is converted to heat, there's no satisfying *smack* sound!

Thanks for passing along that question, Autumn!