Recent content by Vipho

I think the equation you used that is the general solution for the wave equation. In my opinion, the form of the standing wave is give as follows Ψ(x,t)=g(x)f(t)

Oh, I think electric field inside sphere \mathbf{E}= E\hat{\mathbf{r}}=\frac{Q_{tot}}{4 \pi \epsilon_{0} R^{2}}\frac{\mathbf{r}}{r} , (\hat{\mathbf{r}}=\frac{\mathbf{r}}{r}) Hence, \mathbf{\nabla}\cdot \mathbf{E}= \frac{Q_{tot}}{4 \pi \epsilon_{0} R^{2}}\mathbf{\nabla}(...

I think A must be zero, because at r\rightarrow 0, \rho \rightarrow \infty :smile:

\mathbf{E} = \frac{q_{enc}}{4 \pi \epsilon_{0} R^{2}}Is that really Electric Field in all of space? What're electric field inside and outside sphere?

In this case, I think this formula isn't correct. So, \vec{r}=r\cos(\theta)\hat{x}+r\sin(\theta)\hat{y} \\ \vec{v}=\frac{d\vec{r}}{dt} \\ v_x=\frac{d(r\cos(\theta))}{dt}=\cos(\theta)\frac{dr}{dt}+r\frac{d(\cos\theta)}{dt}=\cos(\theta) \frac{dr}{dt}-r\sin\theta \frac{d\theta}{dt} \\...

Hi, magiclink! Is that IB Physics?

I think your working is correct

Thermal capacity is not specific heat capacity

It's not correct. What is area of Gaussian surface?

It's wrong. That must be s=(0.9c+0.9c)/(1+0.81)=1.8c/1.81=0.994c

Electric field inside the cylinder is zero. Because that is conductor material

Homework Statement Calculate the surface charge distribution on a metal disc of radius R having total charge +q. Homework Equations The Attempt at a Solution

m1a= T - (0.3)m1g m2a= 20 - T - 0.3m1+2g-0.3m1g ==>a=[20-(m1+m2)g*0.3-2*0.3*m1g]/(m1+m2)=5/3 (ms^-2) is it right?