Physics Help and Math Help - Physics ForumsScientific physics forums for professionals and students to discuss serious issues and topics regarding physics in theory, practice, study and reality. Students can also find help for homework and career perspectivespossible typo in Ashcroft & Mermin's book- September 17, 2008 Hi, I was taking a look to Appendix M of A&M "Solid State Physics" (Conservation of Crystal Momentum). Seems to me that in Eq. (M.6) the symbol Pi (capital P, defined for the ions) is used in...http://www.physicsforums.com/showthread.php?t=257057&goto=newpost Projectile motion questions help! please- September 17, 2008 Hi, got these as bonus questions but im having a lot of trouble with answering them, so... Can anyone help me with these 2 Neglecting any air resistance 1) A body is projected at an angle...http://www.physicsforums.com/showthread.php?t=257056&goto=newpost Transforming an ODE ...- September 17, 2008 Hi, I have a problem and I am wondering if anyone can help... There is this ODE, where P(x) and Q(x) are known functions: y''(x)+P(x) y'(x)+Q(x) y(x)=0 (1) This ODE cannot be solved...http://www.physicsforums.com/showthread.php?t=257053&goto=newpost meaning of thermodynamical potentials (F,H,G,E)- September 17, 2008 Hello! I'm trying to grasp the "intuitive" meaning of the thermodynamical potetials E,F,H and G, or at least of their connections. As in other threads before mentioned, I learned that you can't...http://www.physicsforums.com/showthread.php?t=257051&goto=newpost Is dark energy constant to emtpy space- September 17, 2008 i've just been reading about dark energy on a site, and it seems it's quite a riddle at present. it stated that the dark energy of space is constant and that the universe is speeding up as the...http://www.physicsforums.com/showthread.php?t=257049&goto=newpost Algebra finding 2 variables- September 17, 2008 1. The problem statement, all variables and givenknown data p=-x2-2x+100 and p=8x+25, find p and x. 2. Relevant equations 3. The attempt at a solution -x2-2x+100=8x+125http://www.physicsforums.com/showthread.php?t=257048&goto=newpost Acceleration question- September 17, 2008 1. The problem statement, all variables and givenknown data A point on a rotating turntable 20.0 cm from the center accelerates from rest to a final speed of .700ms in 1.75s. At t=1.25s, find...http://www.physicsforums.com/showthread.php?t=257047&goto=newpost very important........- September 17, 2008 at any group G show i)o(ab) = o(ba) ii) o(a) = o(cac-1) c in G please i want solvinghttp://www.physicsforums.com/showthread.php?t=257046&goto=newpost Calculate work over a field- September 17, 2008 1. The problem statement, all variables and givenknown data F=(5y+3x-6)i + (2x-y+4)j. find work done by the force on a particle following a triangular path with verticies (0,0),(4,0),(4,3) where...http://www.physicsforums.com/showthread.php?t=257045&goto=newpost units of electric field- September 17, 2008 A possible set of units of electric field, E, in terms of base units is: a) kg x m x s-1 x C-2 b) kg x m2 x s-2 x C-1 c) kg x m x s-2 x C-1 d) C x s-1 e) N x C-1 I believe it is E...http://www.physicsforums.com/showthread.php?t=257044&goto=newpost |