Recent content by scotty_le_b

Hi, So I used the formula ##\nabla \times(\mathbf{c}\times\mathbf{r}) = (\nabla \cdot \mathbf{r})\mathbf{c}+(\mathbf{r}\cdot\nabla)\mathbf{c}-(\nabla\cdot\mathbf{c})\mathbf{r}-(\mathbf{c}\cdot\nabla)\mathbf{r}##. Then the terms where ##\nabla## acts on ##\mathbf{c}## will be zero since...

Homework Statement Without explicit calculation, argue why the following expression cannot be correct: $$\nabla \times (\mathbf{c} \times \mathbf{r}) = c_{2}\mathbf{e_{1}}+c_{1}\mathbf{e_{2}}+c_{3}\mathbf{e_{3}}$$ where ##\mathbf{c}## is a constant vector and ##\mathbf{r}## is the position...

Sorry that's a typo it should read ##\frac{\pi}{8}## in the question not ##\frac{\pi}{2}##. Ah yeah of course that makes perfect sense. Thank you so much!

Homework Statement Let: ##I=\int _{-1} ^{1}{\frac{dx}{\sqrt{1+x}+\sqrt{1-x}+2}}## Show that ##I=\int_{0}^{\frac{ \pi}{8}}{\frac{2cos4t}{cos^{2}t}}## using ##x=sin4t##. Hence show that ##I=2\sqrt{2}-1- \pi## Homework EquationsThe Attempt at a Solution The substitution is ##x=sin4t## which...

Homework Statement Show that the real solution ##x## of $$tanhx=cosechx$$ can be written in the form ##x=ln(a \pm \sqrt{a})## and find an explicit value for ##a##. Homework Equations $$cosh^{2}x-sinh^{2}x=1$$ $$coshx=\frac{e^{x}+e^{-x}}{2}$$ The Attempt at a Solution I reduced the original...

I've got it now there was angle missing from the diagram :L

Homework Statement 3 towns are located at D,F & E; the vertices of an scalene triangle. The bearing of F from D is 48 degrees. D to E=640m and E to F=430m. Point G is located at the end of a south line at F. a)i)Find angle DFG ii) Find angle GFE iii) Find angle DFE b) Calculate angle...

In Scotland St Andrews has one of the best reputations for physics but on their website they only list astrophysics, condensed matter and photonics as research fields. Edinburgh also has a good reputation and it does do research in particle physics. I've also heard that Strathclyde has a very...

Sorry about that I did mean by sending the signal. Thanks :)

I just wondered if someone could programme a computer to, when certain data is inputted, open or close a circuit?

I have been going through my equations and writing them up on the computer so I can refer to that when needed and have go to angular acceleration, velocity and displacement equations yet I don't have very many equations for those topics and I wondered if anyone had some equations for finding...

Oh that makes sense. Thank-You

I was wondering what would g equal on Jupiter if you could stand on its surface? I wrote a computer programme (my 1st one) to work g out anywhere and when i plugged in the numbers for Earth it gave me 9.799 which is correct and for Jupiter it gave me 24.778 but when I looked it up I kept finding...

What I meant by that it was moved up to say a shelf then on the shelf it was not moving. Sorry

Would I be right in saying the following: Potential energy arises from the conservation of energy. To lift a mass you must exert a force counteracting the force of gravity. As it moved and a force was exerted work was done on it. As it is not moving it has no kinetic energy. Due to the...