how do you find the density of a human body?

Question

if you were asked to guess the density of a human body, what number would you give? what common experiences can you draw on to help you with your guess?

thanks to those who answered!

Answer 1

Gotta know volume and weight. So here is a solution.
Fill a bath tub until it is completely full. Throw the body into the water. The water spills over. Talke the body out and measure how much it takes to get the tub full again. This gives you volume. Weight shouldn't be a problem, once you are in the bathroom, use the scale :-)

Answer 2

There is not a formula to calculate this. Penetration of a projectile into a body is a complex process that involves not only mass and density, but bullet shape and composition, the chemical composition of the body, and the spin of the bullet. To estimate things like distance and firearm types, forensic examiners use penetration depth data derived from actual shootings, but more frequently, controlled experiments using ballistic gel, which is thought to behave similar to a human body when shot. HOWEVER.. it looks like you may have been given more than enough data to solve this problem already. If you know the initial velocity of the bullet (v) and the deceleration of the bullet (a), you can find the distance traveled. Were you given the deceleration of the bullet in the body, or prior to hitting the body? If it's the former, you can integrate v=v0+at to find x (the integral of v with respect to t gives x as a function of t), set x0 to be the surface of the body, and solve for v=0. The deceleration is more than likely a function of v, but it may have been simplified for the context of the problem. edit: If you want to find the distance of the shooter, you can do this problem twice assuming you know the deceleration for both flight in air and penetration inside the body. In this case you would be given x, so you could solve for v0 using the deceleration for the body, then solve given the initial and final velocity (which you calculated as v0 above) and solve again for x, the distance from the shooter to the target.

Answer 3

Get a big bucket half full of water. Dip the human completely in. Measure how much the water level rises. With the height multiplied by the cross-section area of the bucket, that gives you the volume of the human. Get the weight too. then density = weight/volume

Answer 4

The density of human body is 1.03 kg/liter or specific gravity 1.03.

Thus we can be drown in fresh river water (density 1.0) without any swimming effort, but will float with nose and mouth outside water surface while floating horizontally with face upwards in a salty sea water with a density of 1.05. The reason people get drowned in sea because of either hypothermia (low body temp.) or getting water into the lungs due to fear.

Thus our body, with 70% water, has an overall density of 1.03.

Answer 5

I'd say its about 1000kgm^-3 at STP. Since humans either just float or just sink in water it would be about 1000kgm^-3. Of course you can work it out roughly using Archimedes Principle.

Fill the bath to the top and when you get in measure the overflow you push out. This is equal to your volume.

Measure your mass on a standard set of scales.

Density = Mass/Volume so divide your mass by your volume to give your density. In SI units this will be kgm^-3.

Answer 6

I sink in fresh water and float in salt. Hence, the density of my body is somewhere between the density of salt water and fresh.
More accurately, submerge the body in a graduated container with water, see how much it displaces. From there it's an easy calculation:
density = mass/volume

Answer 7

find out how much space you take up. usually this is done in a tub of water with a meter on the side, and the difference between the water level when you get in is how much space you take up. then you take your mass, and divide the mass by your volume. you cant just give a number or figure for density, because density is affected by fat and muscle. the more fat compared to muscle, the less dense you are (brains have nothing to with how dense you are yuk yuk)