Recent content by nunos

Find k: 20\frac{d^2x}{dt^2} + \frac{dx}{dt} + kx = 0 when t = 0 - x = 1 - dx/dt = 1 My attempt at this in maxima: (%i1) 20*'diff( 'diff(x, t), t) + 'diff(x, t) + k*x = 0; 2 d x dx (%o1) 20 --- + -- +...

Have exam tomorrow. I know I should have studied before and more, but please help. If you know the answer, please take some time to reply. Thanks very much. Homework Statement There are two charges, q1 = +4.5nC, and q2, ?, which are at distances d1 = 2.5cm and d2 = 2.0cm, from a point...

Anyone?

Another question: An alpha particle is formed by 2 protons and 2 neutrons. If this one alpha particle moves with velocity 6.15e5 m/s in a direction perpendicular to a magnetic field |B| = 0.27T, what's the value of the magnetic force in the particle? So I suppose the formula to use is the...

Thanks espen 180 for your help. I can imagine how boring it might be for someone who is into physics to help a noob like me with such simple questions. I will keep this topic open if I have any more doubt.

That being said, I guess it's A. Since it's being applied a corrent from the battery in point A, the positive pole of the semiconductor P, it will increase the potential there forcing some electrons to pass through. If the semiconductor was of type N, the asnwer would be B, right? I still...

Can anyone please answer, and if possible, explain, this question? Thanks 1. A battery is connected between A and B of a bar made of semi-conductor of type P. The positive electrode was connected in A and the negative in B. What's the current direction? A. from A to B B. in the semiconductor...