Recent content by hnnhcmmngs

Homework Statement: Verify the claim of Section 7.2 that the electrons of a metal collide with the surface at a rate of about 10^30 per second per square centimeter. Do this by estimating the collision frequency of electrons in a 1.00-cm cube of copper metal with one face of the cube surface...

I was shown that adot^2/a^2 = c/a^3, adot = c / √(a), then da/dt = c / √(a) . Then I was told that I have to integrate this, but I don't understand where to go from there or how this will show me that the scale factor grows as t^(2/3).

Homework Statement If possible, calculate the following limit: \lim_{(x,y)\rightarrow (0,0)} {\frac{2x^2 + 3y^2}{5xy}} Homework Equations N/A The Attempt at a Solution [/B] I tried using both parametric and polar equations to find the limit, but neither worked. Setting either x or y...

Then why does the question say "then cooled down to its original temperature"? How am I supposed to calculate the heat removed from the gas?

During the adiabatic expansion the temperature remains constant, correct? And during the isobaric compression the temperature decreases since the pressure remains constant and the volume decreases, correct? So the gas should be heated?

Homework Statement After a free expansion to quadruple its volume, a mole of ideal diatomic gas is compressed back to its original volume isobarically and then cooled down to its original temperature. What is the minimum heat removed from the gas in the final step to restoring its state...

Homework Statement Calculate |u+v+w|, knowing that u, v, and w are vectors in space such that |u|=√2, |v|=√3, u is perpendicular to v, w=u×v. Homework Equations |w|=|u×v|=|u|*|v|*sinΘ The Attempt at a Solution [/B] Θ=90° |w|=(√2)*(√3)*sin(90°)=√(6) Then I tried to use u={√2,0,0}...

Homework Statement Let a and b be non-zero vectors in space. Determine comp a (a × b). Homework Equations comp a (b) = (a ⋅ b)/|a| The Attempt at a Solution [/B] comp a (a × b) = a ⋅ (a × b)/|a| = (a × a) ⋅b/|a| = 0 ⋅ b/|a| = 0 Is this the answer? Or is there more to it?

The current equations above are the right ones. I originally mistyped the question.

How do I make my answer satisfy the 2nd equation? I'm just a little confused because this isn't something we went over in the lecture.

Homework Statement [/B] Find the equation of state of a solid that has an isobaric expansion coefficient dV/dT = 2cT - bp and an isothermal pressure-volume coefficient dV/dp = -bT (Assume the solid has a volume Vo at zero temperature and pressure. Enter a mathematical equation. Use any variable...

I think I'm good on Question 2, and c) is the only right answer. For Question 1, a) isn't right and d) also isn't right. I guess my problem with Question 1 is that I don't know what the main namespace refers to and what the function namespace refers to.

So for Question 1 I guess the only correct answer would be c)? And a) wouldn't be correct since the return value is "After conversion, there are 283.15 degrees", correct? So for Question 2 the only correct answer is c)?

Oh I'm sorry I should have included that! It's Python.

Homework Statement Question 1: def convert(degrees): degrees += 273.15 return degrees degrees = 10 print(convert(degrees)) Which of these statements are true after the code executes? (There may be more than 1 correct answer) a) The value of degrees in the main namespace is 283.15...