Recent content by G-reg

Homework Statement When an electron moves from A to B along an electric field line in the figure below, the electric field does 2.00 10-19 J of work on it. What are the electric potential differences: (a) VB - VA (b) VC - VA (c) VC - VB Homework Equations Ok so I know that the...

and yes, I think that I can you use that conversion. Thanks!

because R is given as 25 [(ft^2 * F * hr)/ (Btu)]

Ah yes the units is the problem. However, now I'm having trouble converting it..here is what I did and it didn't produce the correct answer: .024[W/(m)(K)] x [(.3048m)^2]/1ft^2 x [(1.8K)/1 F] x (1 Btu/1055 J) x [(3600s)/1hr] where F = fahrenheit

Homework Statement The ceiling of a single-family dwelling in a cold climate should have an R-value of 25. To give such insulation, how thick would a layer have to be if it were made of each of the following materials? (a) polyurethane foam (thermal conductivity k = 0.024 W/m · K)...

Homework Statement A certain substance has a mass per mole of 55 g/mol. When 284 J is added as heat to a 32.0 g sample of this material, its temperature rises from 22.0°C to 39.5°C And I know that the specific heat of this substance is 507.14 J/[kg(K)] Homework Equations Q =...

Ok I got the density of the wood but I could not find the density of the oil. For the wood this is what I did.. density of water = 1 g/cm^3 and since the volume is .68 submerged then you divide the .68 by 1g/cm^3 but this method didn't work for the oil

Oh ok! I got it, thanks!

Homework Statement A block of wood with volume V floats in water with 0.68V submerged. In oil the block floats with 0.86V of its volume submerged. Find the density of the wood. Homework Equations \rho = M/V The Attempt at a Solution I'm not really sure about how to...

So it should be.. GM * (T/2pi)^2 = x x - radius of mercury = answer?

Well I guess this guess is wrong because I got a wrong answer.. So where should I go from here?

Oh ok, I think I understand now. So we are looking for 'r'. And we're using the "law of periods" to solve for 'r'. Correct?

The radius.. Are you hinting that the period is the same thing as the altitude?

Yes, the equation is telling you the period of the motion squared. But we're not looking for the period or the mass or the radius..we're looking for the altitude but i can't find an equation in my textbook that would help me out with that.

Homework Statement A orbiting satellite stays over a certain spot on the equator of (rotating) Mercury. What is the altitude of the orbit (called a "synchronous orbit")? Mercury mass = 3.3022 e23 kg Mercury Radius = 2439.7 km Homework Equations T^2 = (4\Pi^2/GM) * r^3 and that's...