1. D

    Converting Density to Molecular Weight

    Greetings all. I am currently in the midst of a Final Acceptance Testing for one of our customers that is purchasing some Density Meters. Physics is not my strong point as I am a Test Engineer and I desperately need some help. Our product is spec'd out such that it reports Density, Pressure...
  2. O

    Density waves in gravitational interacting particles

    My question is about system of infinite number of point like particles with gravitation interaction (classic newtonian interactions). I am interested in propagation of density waves in infinite system which can be considered to be in equilibrium, uniform density, 3D, with emphasis on much larger...
  3. A

    Finding density of an object with the weight and density of fluid?

    Hello, I am a bit stuck with a question "A large container of water initially reads 0.485 kg. A ball is hung in the air from another set of scales which initially read 0.112 kg. The ball is lowered until it is fully submerged. The readings on both scales are now 0.496 kg and 0.101 kg...
  4. H

    Density of Black Hole

    So when I tested the sample question I got the right answer. But doing a practice one I feel like I got the wrong answer - it seems way too high: Black hole mass - 4.31 x 10^6 I calculated Rs to be = 1.27 x 10^7 Average density: P = m/v m = (4.31x10^6) x (1.989x10^30) m = 8.57x10^36 km...
  5. Z

    Raft - Floating / Density problem

    A raft is 200kg.When raft is empty it float on water by 60% of the volume immersed.John weighs 75kg. Can he sit on the raft without it sinking?How much load can the raft take before it's completely under water? What is the density of the raft?
  6. O

    Determine the density of oil and water using a u tube

    Hi, I have a question within physics practical, so I hope your help for solve this priblem. When I do this practical my text books says we should add high density liquid first and then lower density liquid. Also when we messure the heights of the liquids (due to pressure) if I want to...
  7. T

    Magnetic flux density and temperature

    Hello everyone! I am new in the forum; and I am currently studying physics at the high school level. I have a little problem... and I would greatly appreciate any help that you could provide me; The thing is; I have to do an investigation on the relationship between magnetic flux density...
  8. V

    Magnetic flux density and susceptibility

    What is the relation between magnetic suscptibility and magnetic flux density. How can I know how much gauss I will need to attarct a mineral/oxide of given magnetic suscptibilty ?
  9. T

    Density driven flow

    I'm doing some work on density induced flow in porous media. My problem contains a single phase fluid with 2 components (water and a solute). I'm solving the continuity equation along with the advection-diffusion/dispersion eq., Darcy, the equation of state (links between the concentration and...
  10. C

    Relation Between Density of Water and Flow Speed

    Hi, I'm a current IB high school student who is conducting my individual end of the year lab report. For the experiment I decided to test the relationship between the salt concentration (increase in density) of water and the time it takes for it to drain from a bucket. I conducted the experiment...
  11. M

    How to calculate the density of a star's core

    For school I have to calculate certain aspects of a star but now I am stuck at the density. My teacher gave me a formula but I got an unrealistic answer from it. (I know that the formula is very basic) The formula is: P=Md*P(core pressure)/kT Md=average mass of a particle:1,03E-27 Kg...
  12. R

    cross-spectral density function

    from the propagation equation for the cross-spectral density function how we would derive propagation equation for cross specral density funtion? as i am making a fourier transformation of preceding equation but propagation equation for cross spectral density function is at single frequency so...
  13. L

    density of ideal gas

    in this notes , i was told that the PV=mRT , why ? shouldn't PV= NRT , N=number of moles ? it should be PV = m/M (RT) , right ?
  14. T

    How volume charge density can be zero?

    We see in the Laplace equation (del^2)V=0 only if volume charge density is zero. But electric field intensity(E) is not equal to zero. What can be the physical situations to satisfy this equation.?
  15. R

    Probabiltiy density rho(k,t) of k at time t?

    A free 1-D particle has initial wave function psi(x)=A exp(-x^2/4a^2) What is the probability density rho(k,t) that a wavevector measurement at time t will measure k? Please see attachment. I am confused on how to find the probability density of the time dependent wavefunction. Please...
  16. R

    Probability density for momentum

    I am having a little difficulty with problem 9 on the attached problem set. Consider a particle moving in 1D, in an initial wave function of the form psi(x,0)=psi(x)=A exp(-a(x-x0)^2) exp(ik0 x) a) Determine the value of the normalization constant A so that the state is appropriately...
  17. D

    Relating a local magnetic permeability value with a local remanent flux density

    I have read that a steel's magnetic permeability (reported initial or max value) affects the value of its magnetic remanence; a steel with high permeability will have a low remanence and a steel with low permeability will have a high remanence. By remanence, I am referring to the remanent flux...
  18. J

    Weight of object = Force of buoyancy: can I use this when density of object is greatr

    My text book says that for floating objects we can use the equation weight of the object equals to force of buoyancy. They call this equation, floating object in equilibrium on surface. However, what happens when the density of the object is greater than the density of the fluid and the object...
  19. E

    evaluate air density...

    Evaluate air density at pressure of 680kPa (gage) and temperature of 406.29 °C. Any ideas?
  20. Z

    How to calculate fluid rise rate and Ra during convection due to density difference?

    I would be very grateful for some help with what is probably a simple problem. I'm a bit of a fluid dynamics newbie. I want to consider natural convection due to density differences, not "forced" convection. For example, a liquid that rises because it is less dense than the surrounding solid...