Bed of Nails question?

I have a question. In a bed of nails demo (where a guy lies on his back on a bed of nails and a guy smashes a cinder block and the guy appears unharm), if you use a smaller brick would it be more dangerous or less?Bed of Nails question?
It is a question of momentum. The smaller block would move more sharply, and therefore impart more force to the person below.





We know that Force = mass x acceleration.





Since the force of the hammer blow would be more or less constant, the larger block would presumably have a larger mass, and so it would accelerate more slowly; that is, it would move less. Since it moved less, it would impart less force.





And, as another respondent said, the larger block would also impart that force over a larger area, so the force per square inch or cm would be less for the larger block, too.Bed of Nails question?
This ';trick'; works on the following principles: the body weight is evenly divided between all the contact points (the nails). Say a person is 200 lb on a 200 nail bed, then there is only 1 lb applied to any given nail. The end of a nail is actually rounded and the pressure on the skin applied by the tip of the nail is below the force needed to puncture the skin. The trick would not work if there were 5 nails or if each nail was filed to a needle point.





Now to your question: when someone breaks a cinder block on the person's stomach (who thinks of those things?), the force is increased. It's as if the person was temporarily heavier. The heavier the block or the higher the block speed, the higher the force. Replace the cinder block by a car and you get the idea! If you apply enough force, the person will be very sorry he agreed to lay down on the nail bed.





A smaller brick of equal weight would not alter the basic premises: the pressure on a given nail would increase negligibly.






definitely smaller brick will be more dangerous. it wudnt have effected much if the body had been a rigid structure, that wud have helped to spread the blow equally in all parts of the body. but human body is elastic. the moment the happer hits the brick the brick will equally spread the blow on the body, but the body wud not do so, the area under the brick will instantly move down on nails before it is spread to whole body leading to an eventful evining
I think more dangerous because all the force would be concentrated on one part of your body, pushing that part into the nails
The only thing that matters in this case is the number of nails in the bed. The size of the block shouldn't matter at all.