Recent content by kpx001

Mass = Volume * Density = (Pi*(100*10^-4 cm)^3)/6 * 4.23 g/cm^3 = 2.214 * 10^-6 g per particle 1g / 2.214 *10^-6 g / particle = 451671 particles in 1 gram that are 100 micrometers. SA = pi*D^2 = pi*(100*10^-6 m)^2 * 451671 = .01419 m^2 is the SA of 1gram ? still a bit iffy about part 2 if...

Yes Mass = Volume * Density = (Pi*(100*10^-7 cm)^3)/6 * 4.23 g/cm^3 mass 1 particle= 2.214 * 10^-15 g mass 1 g = 2.214 * 10^-15 / 79 so 1.68 *10^7 particles to get 1g mass?

Homework Statement Calculate the surface area of 1g of powder with a size of 100micrometer. Assume the particles are spherical. Then estimate the percentage of TiO2 molecules at the surface of the particle (relative to the total number of TiO2 molecules in the volume of the particle) for the...

Hey sorry but I've been looking through several online resources and books but I cannot find a dumbed down explanation of how a frank reed source generates dislocations. Like what is the shears doing and the burgers vector?? I am so confused can someone enlighten me please? thanks

Homework Statement Ok so basiclly I know how to do the problems, but I'm confused when to make the force negative and when to ignore the negative. forexample: http://yfrog.com/jastaticsprobp solving part a: Moment at A = -24*39 -(-14*39) = 2028 notice how i had to do -(-14*39) to...

True or false: a large plate of a brittle material fractures at a higher applied tensile stress as compared to a small plate of the same material. and True or false: the critical stress for a fracture of an internal crack of length 1mm is less than the critical stress for fracture of the same...

i am guessing that they want me to use the graph to get another plot with concentration vs depth... then from that i am to get hardness vs depth. other than that i am confused as well. i have D and D_0 and Q_d and R and T. from this i can get concentration using flicks 2nd law.. but what about...

Can anyone help me solve this problem? I am unsure on what to do http://yfrog.com/j5flicks2ndp

Homework Statement which of the wave functions describe a wave that moves in the -x direction y(x,t) =Asin(-kx-wt) y(x,t)=Asin(kx+wt) y(x,t)=Acos(kx+wt) Homework Equations wave function The Attempt at a Solution I know B and C both move left looking at the phase (kx+wt) because...

oh so it would be k=2n/lambda ... the 2n = 2(2pi) and the lambda = 2pi?

I now understand the relationship, but I want to know how to do it the mathematical way.

Homework Statement The figure shows a snapshot of three waves traveling along a string, where x,t are in SI units. The phases for the waves are given by... the picture and problem is in this link http://img339.imageshack.us/img339/2407/phys1prob.th.png Homework Equations (kx-wt)...