Recent content by bobred

You are correct TSny, I was rushing and didn't check it properly.

I have seen similar values too, but the value was given on a sheet of constants. Can't see where the problem is.

Yes there is a typo, the calculation was correct though, it should be n_0=\frac{N_D-N_A}{2}+\sqrt{\frac{(N_D-N_A)}{2}^2+n_i^2}

Homework Statement For silicon at T=300K with donor density ND=2×109cm−3, acceptor density NA=0 and ni=8.2×109cm−3, calculate the equilibrium electron and hole concentration Homework Equations n_0=\frac{N_D-N_A}{2}+\sqrt{\frac{N_D-N_A}{2}^2+n_i^2} p_o=\frac{n_i^2}{n_0} The Attempt at a...

Thanks for the replies. I have 5 Isotopes but two have multiple peaks, I shall include them and see if this improves things and revert back to a linear fit.

Hi I have some data from a gamma spectroscopy lab and using a series of known radioactive sources I obtain a calibration curve. The equipment is a scintillation crystal coupled to a photo-multiplier tube connected to a multi-channel analyser to obtain an energy spectrum. Using Excel I add a...

Homework Statement I have the two functions below and have to find the convolution \beta * L Homework Equations Assume a<1 \beta(x)=\begin{cases} \frac{\pi}{4a}\cos\left(\frac{\pi x}{2a}\right) & \left|x\right|<a\\ 0 & \left|x\right|\geq a \end{cases} L(x)=\begin{cases} 1 &...

Looking into it now thanks.

Hi, yes I'm asking how to relate the change in depth of the float to the change of force on it from the weight of the chains.

Homework Statement There is a submerged float which is held in equilibrium by three hanging chains (see attached), a portion of the chain hangs below the float. Ultrasound directed onto the top face of the float (which is concave with angle α) and the float is displaced downward proportional to...

HI, sorry H(r).

Homework Statement Find the equations of motion for both r and \theta of Homework Equations My problem is taking the derivative wrt time of and \dfrac{\partial\mathcal{L}}{\partial\dot{r}}=m \dot{r} \left( 1 + \left( \dfrac{\partial H}{\partial r}\right)^2 \right) The Attempt at a...

So setting the acceleration \ddot{r}=0 leaves a constant r and \dot{\phi} which allows the uniform motion.

Differentiating a constant is zero. I was thinking about the equations in isolation to each other and not as part of a system. So v=r \dot{\phi}=r_0 \Omega I just need to show that the equations of motion lead to this.

Homework Statement A particle moves on the surface of an inverted cone. The Lagrangian is given by Show that there is a solution of the equations of motion where and take constant values and respectively Homework Equations The equations of motion and are (1) (2) So can be...