How to determine the effect of counterforce on the angle of force

[avgr]

Homework Statement

I am a in Rabbinical college and this question came up. In the laws of ritual slaughter to be a valid slaughter the pressure on the knife must be at a 45 degree angle or less in the downward direction. In other words more or equal force going across the neck than downwards into the neck. What formula would show the effect the counterforce of the neck will have on the direction the knife is moving?

Relevant Equations

I am unsure of which equations I would need to use

Can anyone help me with a formula that would show the effect the counterforce of the neck will have on the direction the knife is moving, to be able to determine what a cut in a given direction what will be its direction of force?
(I apologize for not following the guidelines for homework questions, as that wasn't possible for this type of question.)

 

[berkeman]

Homework Statement:: I am a in Rabbinical college and this question came up. In the laws of ritual slaughter to be a valid slaughter the pressure on the knife must be at a 45 degree angle or less in the downward direction. In other words more or equal force going across the neck than downwards into the neck. What formula would show the effect the counterforce of the neck will have on the direction the knife is moving?
Relevant Equations:: I am unsure of which equations I would need to use

Can anyone help me with a formula that would show the effect the counterforce of the neck will have on the direction the knife is moving, to be able to determine what a cut in a given direction what will be its direction of force?
(I apologize for not following the guidelines for homework questions, as that wasn't possible for this type of question.)

Welcome to the PF.

You win a prize for one of the more unusual study questions ever... Keep in mind that the thread may be shut down at some point, since the subject matter may be offensive to some of our members.

https://en.wikipedia.org/wiki/Ritual_slaughter#Jewish_and_Islamic_ritual_slaughter

I'm not seeing the 45 degree downward direction requirement in the Wikipedia link (there must be different kinds?). Can you post a link to the requirements you are asking about? I would imagine the goal is to make the killing of the animal as quick and painless as possible.

 

[jedishrfu]

An odd parallel to this question is the martial art cutting demonstrations where a student would lay on his back on a bed of nails. Another student or more likely the sensei would strike the stomach of the prone student without cutting the student. The trick is to not slide the blade during the strike and nothing will be cut.

Another would be the optimal katana striking angle. There is no formula provided although 45 degrees is common:

https://www.wikihow.com/Use-a-Katana-Properly#:~:text=Hold the katana on the,of you at chest level.

 

[jedishrfu]

Here is another katana striking analysis:

https://shinkanryu.org/kesagiri-anatomy-of-a-sword-strike/

and this:

https://www.claireryanauthor.com/blog/2539/the-physics-of-the-cut

 

[avgr]

Welcome to the PF.

You win a prize for one of the more unusual study questions ever... Keep in mind that the thread may be shut down at some point, since the subject matter may be offensive to some of our members.

https://en.wikipedia.org/wiki/Ritual_slaughter#Jewish_and_Islamic_ritual_slaughter

I'm not seeing the 45 degree downward direction requirement in the Wikipedia link (there must be different kinds?). Can you post a link to the requirements you are asking about? I would imagine the goal is to make the killing of the animal as quick and painless as possible.

This

https://en.wikipedia.org/wiki/Shechita#Forbidden_techniques see drasah. The details of drasah is not elaborated there, it is too broad a topic.

And you are correct, one reason is to make the slaughter as painless to the animal as possible.
(On the aside the slaughter necessitates cutting the carotid artery, which disconnects blood flow to the brain. The animal goes unconscious before the brain can register the cut of its nerves. There is no pain what so ever. See The Coming Revolution by Rabbi Zamir Cohen, Ritual Shechita.)