Recent content by adichy

Im missing some units, in which case L ∝ M^3.5 I was quoting the mass-luminosity relation M/M_solar =(L/L_solar)^a, what i wasnt sure about was using a=3.5 since there is not information regarding the type of star. A is the surface area of the star=4piR^2 and σ is the stefan Boltzmann constant

Homework Statement Consider a star with a density distribution ⍴ = ⍴_0(R/r), where R is the star’s outer radius. The star’s luminosity is L, and all of its energy is generated in a small region near r = 0. Outside that region the heat flow is constant. a) Find the surface temperature of the...

Homework Statement Show that, owing to the rotation of the Earth on its axis, the apparent weight of an object of mass m at latitude λ is : m((g-ω^{2}Rcos^{2}λ)^{2}-(ω^{2}Rcosλsinλ)^{2})^{1/2} where ω is the angular velocity of the Earth and R its radius. The first space travellers to reach...

Ahh, of course, they're supposed to be orthogonal. I was under the impression that the magnetic field was in the z direction.

Sorry, what I meant was from doing the calculation, I found the answer to be zero. That's what I found confusing. It shouldn't be zero. Am I assuming wrong that d/dx and d/dy of B will come out as 0 since it's differentiating constants as there are no x or y variables in the field? Basically...

Homework Statement The electric and magnetic fields in a plane wave propagating in free-space in the z-direction can we represented by (in complex-exponential notation) E(x, y, z, t) = E_0 e^i(kz−wt+d ) and B(x, y, z, t) = B_0e^i(kz−wt+d ) Starting with the Ampère-Maxwell law, ∇ x B =μ_0 ε_0...

Homework Statement As an application of TD and to demonstrate the power of the formalism of differential forms, show that if one defines the ideal gas temperature TI (T) from the ideal gas equation p V = N KB TI(T); this is related to the absolute temperature T (from the second law) by TI...

oh sorry i forgot its squared... ahh divide both the expressions to find the ratio?

im not sure how eliminate the distance F_e=kqq/r F_g=Gmm/r^2 equating those 2 will still leave me with distance I can't think of any other formula for F_e that doesn't require finding the electric field or using the distance

Homework Statement An alpha particle has a mass m = 6.64x10^-27 kg and a charge q = +2e. Compare the force of electric repulsion between two alpha particles and the force of gravitational attraction between them. Explain briefly why the gravitational force is ever significant, given its...

Homework Statement Find the general solution to the differential equation \frac{d^2y}{dx^2} -2*\frac{dy}{dx} +2y =g(x) where g(x) = −14 cos(2x) − 2 sin(2x) Homework Equations The Attempt at a Solution ive found the homogenous solution which is y=e^x (ae^ix +be^-ix) what I...

Homework Statement i have a graph or r against V and to make it a straight plot i then plotted ln(r) against V, Homework Equations The Attempt at a Solution the problem is i dnt know how to find the capacitance from the graph. it definitely isn't the gradient or the point of...

titled it wrong, can anyone tell me how to change it >.<

Homework Statement By making the change of variables x where x = sin \theta, calculate the indefinite integral \int \sqrt{1-x^2} expressing you answer as a function of x. Hence find the solution(s) to the differential equation \frac{dy}{dx} \frac{d^2y}{dx^2} +x =0 Homework Equations...

noted: no more baby talk...can slip out sometimes unawares Thanks for the help, much appreciated