Recent content by kel

so, I should differentiate the inner bracket first and then add the answer to this in a second differentiation??

Homework Statement I'm fairly new to mathematica and have been trying to input the following equation, but keep getting an error message stating that I have only 2 arguments when I need 3 or more. BTW, this is in relation to astrophysics Homework Equations function is: f(x) = (1...

If you mean that I have missed 't' out, then that is because both w1 and w2 are being multipled by t, so I factored it out

Homework Statement Hi, I've worked this out (I think) but would appreciate someone xhecking over my method. U 235 and U 238 found in ratio of 7.3E-3 to 1, but thought to have been produced equally (ie equal quantities) half lives are 1.03E9 and 6.49E9 respectively. Estimate time since...

ok, from my notes there is an example using sodium chloride which gives the energy as E = 7.9 (cohesive energy) - 5.1(ionisation energy) +3.6 (electron affinity) = 6.4ev What I want to know is, is the cohesive energy generally the same for all molecules? if so, then I can use the...

Homework Statement The ionisation energy of Li is 5.39eV and the electron affinity of F is 3.40eV. Give a lower bound for the modulus of the crystallisation energy of Li+F- Homework Equations Not entirely sure of the equation to use, but have this one in my notes: U = -...

Homework Statement The ionisation energy of Li is 5.39eV and the electron affinity of F is 3.40eV. Give a lower bound for the modulus of the crystallisation energy of Li+F- Homework Equations Not entirely sure of the equation to use, but have this one in my notes: U = -...

I have the truth table, but could you please explain how to use the NOR gate to make an AND and an OR gate. This I think is where my difficulty lies, I can't see how to get the inputs to give me the right output so that I can make a XOR gate. But if like you say it's possible to make a NOR...

Homework Statement Part 1 - give the truth table for an XOR port part 2 - implement the results (from part 1) using only NOR ports Homework Equations The Attempt at a Solution So far I have tried combining NOR gates and have even used single input NOR gates (effectively turning...

Homework Statement The element Po forms a crystal with a simple cubic structure of spacing (3.34A). What is the maximal wavelength of radiation that is diffracted from a powder of that crystal Homework Equations N/a, however I thought that it may well be something to do with the bragg...

I've just written the question as it is on my sheet. Eitherway, I still need help. Thanks

Homework Statement A pair of twins live in (city). one drives around the world in his fast blue car, leaving the city in a fixed direction with a constant velocity v. The proper circumference of the Earth is 2PiR - ignore the rotation of the earth. 1 -What is the age difference between the...

the integral file is the one that I wrote out - wasn't sure if I've done the math correct before I move onto the next part.

just realized that n=2 and alpha=2/a0, but still need some guidance on the calculus cheers

Homework Statement Hi, I'd doing question 1 of the attached sheet and just wondered if someone could help me out. I'm a bit unsure of my calculus and need it reviewed, alsoam not entirely sure how to break down my workings (using the supplied equations in the hint) to find C. So any input...