Doing a project, need some insight to some physics things

[GTOM]

I have a related question, realistically, how much acceleration could a human body provide? (Needed for dodge bullet equation.)

 

[Drakkith]

Which is more aerodynamic, sharp edges or curves?

You probably want curved surfaces, as you can shape them to minimize various types of turbulence, vortices, etc. Curved surfaces also withstand debris impacts better than a sharp edge does.

I have a related question, realistically, how much acceleration could a human body provide? (Needed for dodge bullet equation.)

Your question is a bit vague, but an olympic sprinter's acceleration for the first 10 meters of a 100 meter race is around 3 m/s². The acceleration of a hand or a foot would be greater than that.

 

[GTOM]

You probably want curved surfaces, as you can shape them to minimize various types of turbulence, vortices, etc. Curved surfaces also withstand debris impacts better than a sharp edge does.
Your question is a bit vague, but an olympic sprinter's acceleration for the first 10 meters of a 100 meter race is around 3 m/s². The acceleration of a hand or a foot would be greater than that.

Thanks, although i wonder. If humán body can't produce more than 10 m/s2 how can it jump? Or perpendicular to a surface is a better case for gaining momentum?

 

[Drakkith]

Thanks, although i wonder. If humán body can't produce more than 10 m/s2 how can it jump? Or perpendicular to a surface is a better case for gaining momentum?

Jumping is not running. For one, you can use both legs at the same time when jumping, whereas in running only one leg provides acceleration at a time. Also, peak acceleration is probably larger than 3 m/s² when the runner initially starts running. I'm not sure how much larger though.

 

[Jiku Araiguma]

Now, I need some thoughts on punch/impact physics. How many ways are there to produce 4000N of force with a single punch? How fast would a normal fist be going? How big/small would a fist have to be to cause damage at that force? How much damage would be caused?

 

[Drakkith]

Now, I need some thoughts on punch/impact physics. How many ways are there to produce 4000N of force with a single punch?

Peak force? Average force? Elite boxers can generate a maximum peak force of about 4000 to 5000 N, so that gives you an idea of what kind of level you need to be at.

How fast would a normal fist be going?

That depends on how heavy the person's fist is and how long it takes to decelerate it during impact, which depends on several other variables, so I don't really know. A fast boxer punch ranges somewhere around 20-30 mph, though.

How big/small would a fist have to be to cause damage at that force?

Just about any sized first can cause damage when you're exerting a force of 4,000 N on a portion of someone's face, head, and body.

How much damage would be caused?

That depends almost entirely upon where the blow struck. Without a glove, a punch like this can easily cause a concussion, break bones, and knock out teeth. Just look at the injuries punches cause in boxing or other martial arts.