Recent content by xiankai

a. this may not be very technical but say, the temperature of the environment may also play a part in the heating factor? b. you could probably that your heat body is heated in an enclosed environment (don't know the thermodynamic terms), since i think the specific heat capacity of copper...

one way is to imagine where the current is going. the shortest route from F-G is direct via R4. another path is R3+R5, which are in series and together, are parallel to R4. next, R1+R2 is parallel to R3, so we revise our calculations for R3+R5.

Fnet = menginea1 + 6mcara1 now since the pulling power of the engine (the force it can exert) is assumed to be constant, Fnet = menginea2 + 4mCARa2

u're finding the pressure exerted by 6m of water?

are you sure your data is correct? your working is correct except for the part where you should have put 80 instead of 60 seconds. plus the part about 15 W and 24 KW doesn't match...

for a variable to be proportional to another, it implies a relationship of A = kB (or B = pA) where A and B are the related variables, and k or p is the constant depending on how you write the equation. thus they can be related as a straight linear line. the radius does change when the period...

it looks the square of the period is proportional to the radius, rather.

a = (v-u)/t given u = 0, and v = s/t a = s/t^2 = 0.4 ms^-2 (assuming non-frictional planar flat surface, linear acceleration) thats what i think, at least

Homework Statement 1. In a region of space, a particle with zero total energy E has a wavefunction ψ (x) = A x exp - (x2/L2) a) Find the potential energy U as a function of x b) Make a sketch of U(x) versus x Homework Equations time independent Schrödinger's...

we must include the rest mass of the electron?

since it is defined (from what i can tell) as h/p, is it interchangeable with the classical wavelength in equations involving waves in general? or is it a special separate case for matter? that is, for photons we have the following equation: E = hf E = hc/λ can the same equation be...

got it. thanks for the quick reply!

if you differentiate kinetic energy wrt. to velocity, you will get momentum as the result. what i wanted to ask is that, how can this physically explained? that kinetic energy can be viewed as the rate of change of momentum for a change in velocity? is there any analogy?

for ions with more than one proton ie. He+, Li2+ and Be3+, doesn't the extra charge factor into the equation? because it seems only the elementary charge is http://en.wikipedia.org/wiki/Bohr_radius" , hence rendering it independent of amount of positive charge present.

i used to have that too, it was more frequent when i was younger than now when I am older. i felt like a tiny insignificant speck in a corner, and how everything is bearing down on me. i still recalled the time when i woke up late at night, yelling about how a train was about to crash through...