Fluid dynamics.. does anyone know the answers or how to solve these problems?
At low pressures there is a significant difference between the densities of liquids and of gases. For example, at 1 at, the densest gas known to the author is uranium hexaflouride, which has M = 352g/mol; its normal boiling point is 56.2 C, assuming that it obeys the ideal gas law. The least dense liquid known to the author is liquid hydrogen, which at its normal boiling point, 20 K, had a density of 0.071g/cm^3. Liquid helium also has a very low density, about .125g/cm^3 (at 4 K). Excluding these remarkable materials, make a list of liquids which at 1 atm can exist at densities of less than 0.5g/cm^3.
14) For some oil and gas drilling operations we need a high-density drilling fluid (called "drilling mud"). What is the density of a mud that is 50% wt. water, 50% wt. BaSO4 (barite), SG of barite = 4.49.
I know the answer is 102 lbm/ft^3, but I don’t know how to go about solving the problem.
15) Why are specific gravities most often referred to the density of water at a temperature of 4 C instead of at 0 C?
19) A cubic foot of water at a temp of 68 F (20 C) weighs 62.3 lbf on earth…
a) What is its density?
b) What does it weigh on the moon (g = 6ft/s^2)?
c) What is its density on the moon?
27) The slug and the poundal were invented to make the conversion factor (mass/length) / (force/time^2) have a coefficient of 1. A new unit of length or a new unit of time could just as logically have been invented for this. Let us name those units the "toof" and the "dnoces". What are the valies of the toof and the dnoces in terms of the foot and the second.
I also know the answer to this is the toof = 32.2 ft, and the dnoces = s/sqrt 32.2, but I don’t know how to show this.
Any help on these problems would be awesome, thanks a bunch! =]
April 22nd, 2010 at 8:07 pm
Well I know # 15
and that is because water is most dense at 4 degree C. When the temperature goes toward 0 deg C the water starts EXPANDING in getting it’s structure to line up to be ice. Ice is 9 % lighter than water I think per volume
14) water weighs 62.43 lbs/cubic foot
BaSO4 weighs 4.49 as much as water
62.43 * 4.49 = 280.31 lbs/ cubic foot for BaSO4
50% by weight for each=
half of the cubic foot is water = 62.43/2 = 31.215 lbs
barium sulfate weighs 4.49 times more so take 280.31/ 4.49
= 70.077 lbs for the BaSO4 portion
add the two 1/2 cubic portions together:
70.077 + 31.215 = 101.292 lbs/ft^3
(real close to your number)
19)
a) density of water is 62.3 lbs/ ft^3
b) weight is different than mass so acceleration on earth 32ft/s^2
So acceleration on moon 6ft/s^2 / 32ft= .1875 or 18.75% of weight on earth = 62.3 *.1875 =
= 11.68 lbs water weight on the moon
The next element on the list after helium is Lithium and it’s density is 0.512 g/cm^3.
http://en.wikipedia.org/wiki/Lithium
27) I’m having a hard time understanding the question, because the way it is wrote why can’t you just substitute in the value for a 1 slug= 1 *lbF *s^2 / ft = 1 toof
and the value 1 poundal = 1 lb*ft* s^2- = 1 dnoces ?
They both already are wrote in terms of the lb and second
I’m a little confused on this one