Recent content by dikmikkel

Hi, Suppose I have a dissociative adsorption reaction and want to find the free energy change ΔF, this can be written at constant temperature: \Delta F = \Delta E -T\Delta S Now given the adsorption energy \Delta E_{ads} I would like to extrapolate the Free energy assuming that the adsorbate...

Homework Statement I have an adsorption reaction A+* \leftrightharpoons A^* Then I am to finde the rate constants and these should be given by an Arhennius relation, e.g. from left to right in the reaction: k_+ = f_+\exp(-\Delta E_a/k_bT) where the delta energy is the activation energy and...

The 2nd question. Find it yourself, it must be this equation you are to use, else it is complicated I think. 3rd question: Newtons 1st law says that a particle which is affected by no force is continuing with the same velocity along a straight line, thus if it had e.g. v = 400m/s as velocity it...

Maybe. m=15 kg and the force F=45N, it accelerates by 2m/s/s then F_{net} = ma = 15\text{kg}\times 2\text{m/s^2} = 30 \text{N}

Edit: What I wrote was nonsense sorry.

Equilbrium is when there is no motion right? So torques must cancel out and all forces aswell, this leaves two vectorial equations: \sum\mathbf{\tau} = \vec{0} \sum\vec{F} = \vec{0} Now the picture has two wires holding it up. The weight of the picture is w = mg (in y dir.)...

So the magnetic force is \vec{F} = q\vec{v}\times \vec{B} q is the positive charge. I do not know what straight ahed means, I assume that you have a sketch. Your thumb on the right hand shall be in the direction of the velocity and your index finger along the magnetic field, then your middle...

Taking the inverse cosine of a cosine gives the argument to the inverse cosine. Then you would use the sum of angles trigonometric formula.

I think that since you are working with idel gasses, you can dervie most of the stuff from 3-4 equations, namely: The ideal gas law : pV = nRT The Laws of thermodynamics.(2-3 laws is useful). If you want to find the Work done during a isothermal(T constant) step e.g.: W =...

Follow up: Maybe I shall choose some k and just plot a constant, but it seems silly.

Homework Statement I have an energy function as follows: E = \dfrac{\hbar^2}{2m_e}k_x^2+E_0\left(n_y^2+1\right) Where E_0 = \dfrac{\pi^2\hbar^2}{2m_eL_z} I am asked to plot this energy for x\in ]-L_z/2;L_z/2[ I know everything but not the relation between k and x?. The Attempt at a...

a) Are quantum effects relevant for the air around us? "Formulas": The Fermi energy of athmosperic air: \epsilon_F = \dfrac{\hbar^2}{2m_{air}}(3\pi^2C)^{2/3} Attempt to solve: I calculated the fermi energy to : \epsilon_F = 1\times 10^{-25}\,\text{J} And k_bT = k_b 293\,\text{K} = 4\times...

Homework Statement Show that the direction [hkl] is perpendicular to the plane (hkl) in a cubic system. Homework Equations None, maybe cross product The Attempt at a Solution I've tried to define the crystal translation vectors(cubic means a=b=c): \vec{a}_1 = a\hat{x}\\ \vec{a}_2...

To check if something is a solutions means: substitute the solution in the system and check that the LHS equals the RHS.

You can set up the cross product and substitute back in t in terms of x,y,z.