Recent content by hola

OK, so I guess the presenter didn't really do anything. He found a focusing point to the waves on the opposite side of the lens, though, somehow. But how about Poynting vector? And why is it difficult to create a LHM at optical frequencies? Also, what about materials with only one parameter...

Oh, I also should mention, looking at his abstract, that he had source and receiving dipoles to find the strength of the exiting waves. I think he had a transmission map to find the resonance frequency. He generated a EM wave field strength map, and found a focus point.

He used two perpendicular cross wire resonators. He said that as long as these copper wires didn't touch, they would act as an interacting pair. Something about an LC resonator. At a frequency higher that the resonance frequency, permeability is drawn negative by the magnetic field. I think...

I was at a high school science symposium, and some kid presented about metamaterials, a structure that shows a negative index of refraction, n. So I think his project was pretty good and all, and he had a good understanding: he had apparently created a new composite structure with neg. n without...

I see from various publications that the two approaches to obtaining a negative refractive index is thru photonic crystals and the lattice structure method. The lattice sturcture requires unit cells of much smaller wavelength than the EM wave that is propagating. So the interest in new designs...

I also did some research on metamaterials. Zz mentioned their construction thru conducting rods, split rings, etc. I have found that these split ring resonators mentioned compose the unit cell of the lattice structure of the actual material that displays a negative index of refraction. Would...

Gaseous hydrofluoric acid reacts with solid silicon dioxide. My work (did a double replacement): HF+SiO2------>H2O+SiF But this doesn't look right. Why? 1. It looks weird. 2. How much valence electrons is Si supposed to have? 3. We're not dealing with solutions. Anyone know the answer?

What is the pH of a solution containing 50.0g of (Na_3)(PO_4) in a liter of solution? We are given that (Na_3)(PO_4) is very basic.

I need to include net ionic eq, phase symbols, etc. 1. Sulfur trioxide is heated with carbon dioxide. 2. A solution of strontium chloride is mixed with a solution of sodium sulfate. 3. Hydrochloric acid is added to sodium hydroxide My work: 1. SO3(g)+H2O(l)---->H2SO4(aq) 2...

Could someone check my work? I need to write out the net ionic equation, when applicable. Diphosphourous trioxide gas is bubbled into water. My answer: P_2 O_3 + 3H_2 O ------> 2H_3 PO_3 A solution of sodium hydroxide is added to nitric acid. Na(OH) + HNO_3 -------> HOH + NANO_3 For...

I know, but I can't solve for a in terms of t.

Source: PhysicsBowl A chain of length 2d and mass 2m is placed over a frictionless table such that half of the rope is on the table; the other half dangling, and it is just starting to accelerate. Find its acceleration as a function of time. I couldn't get this one. I tried net force = ma...

1. Use substitution x = e^t to transfer equation into one with constant coefficients and solve: x^2 y'' -3xy' + 13y = 4 + 3x My work: Okay, we have e^2t y'' - 3e^t y' + 13y = 4 + 3e^t. Now I am absolutely stuck. No idea how to solve it. Help!

Okay: For air, I got: Change in temp: 7.0 C specific heat: 29.1 J/molK mass= 839*10^5 g (should I convert this into moles?) For methane: specific heat: 4.18 j/molK I need to solve for mass, right? But I don't have temperature change in methane? HELP! please,:smile: ?

Suppose you want to heat the air in your house with natural gas (CH_4). Assume your house has 275 m^2 of floor are and ceilings are 2.5 m from floors. The air in your house has a specific heat capacity of 29.1 J/mol K. The number of moles in the house can be found by assuming the molar mass of...