Recent content by eximius

I'm not looking for the answer, I just want some help with understanding the question. The main thing I'm stuck on is the characteristic binding energy and the characteristic molecular size. I've tried searching for these but I'm finding a lot of different stuff. Homework Statement All to...

Homework Statement A traveling wave f(x,t) = ei(kx -wt). Show that the real part of the wave can be written as cos(kx)cos(wt) + sin(kx)sin(wt) Homework Equations Euler eiθ = cos(θ) + isin(θ) Also ei(θ1+θ2) = eiθ1 . eiθ2 The Attempt at a Solution The - symbol is throwing me...

The vector (2,2,2) doesn't have magnitude 2*√3, it has a magnitude of √(2^2 + 2^2 + 2^2) = √12, doesn't it? Is the intention to get the unit vector? I really don't understand at all. If you could please just tell me, I'm simply not getting it. v and r are vectors, ω is a scalar If P-Q = r, then...

Ahhh so the magnitude is √3. Therefore ω= 2*√3. So v = 2√3 * √6 = 6√2 = 8.49m/s ? I'm sorry if I seemed annoyed or something. I was just confused and frustrated. Edit: I have r in vector form, I need ω in vector form. The magnitude of ω is 2. So I need to get the vector form from this. But...

Is it something to do with using P-Q as the normal to the plane and discovering the plane's equation with N.(x-Px) = 0? Or something like that?

Erm... So what is the answer then? Am I even right in thinking that P-Q is equal to r? How do I get v? Sorry but you're being very cryptic and I just don't get it...

So P-Q = (1,-1,2) and w = (2,2,2). Therefore v = (6,-2,-4)m/s ? I understand your reply but it doesn't really tell me what to do.

Homework Statement A rigid body is rotating with angular velocity 2 rad/s about an axis in the direction of the vector (i + j + k) and passing through the point Q = (0, 1, -1) on the body. Find the linear velocity of the point P = (1, 0, 1) on the body. (You may use the result v = ω x...

Thanks for the reply it really does help. So it seems that I've done it correctly. But does anyone have any idea of the name of the formula, where it comes from, the names of the a and b constants etc? Am I right in thinking that it's from the "Steinhart Hart equation"?

I'm not sure if this is the right place to post this, but it seems to be the best fit. Homework Statement I'm trying to write a lab report about how resistance varies with temperature. I used liquid nitrogen to cool a copper coil and a semiconductor(thermistor) from room temperature to...

Homework Statement I'm trying to determine R_0 and alpha (temperature coefficient of resistance) from results I obtained through an experiment. We have been given the first equation and been told that R_T is the resistance at temperature T in kelvin. R_273 is the resistance at temperature 273K...

I used the 2 equations to calculate the position of the particle at t = 1, I get (-18,22). This shows that the particle is traveling North West. Doesn't the negative value of x indicate that I need to resolve the angles to the 2nd quadrant?

Therefore the answer to B will be: θ = tan-1(8.58/14.04) = 31.43 degrees Relative to positive x-axis = 180 - θ = 148.57 degrees And the answer to C will be: θ = tan-1(22/18) = 50.71 degrees Relative to positive x-axis = θ + 90 = 140.71 degrees Is that right? And thanks for the help, it's...

Homework Statement A 0.39 kg particle moves in an xy plane according to x(t) = - 13 + 1 t - 6 t^3 and y(t) = 28 + 5 t - 11 t^2, with x and y in meters and t in seconds. At t = 1.0 s, what are (a) the magnitude and (b) the angle (within (-180°, 180°] interval relative to the positive direction...

Homework Statement [PLAIN]http://img705.imageshack.us/img705/4462/40230468.jpg Homework Equations Power Factor = True Power / Apparent Power f = 1 / (2*pi*root(LC)) Z = root(R^2 + (Xl - Xc)^2) = R The Attempt at a Solution a)i) 1? Because it's purely resistive, but this...