


2. The acceleration equation We have derived in lectures the Friedmann and fluid equations, that describe...
3. The Cosmological constant When formulating general relativity, Einstein believed that the Universe was static. In order to arrange a static Universe, he proposed a change to the equations, something he would later famously call his "greatest blunder". That was the introduction of a cosmological constant, A, to the Friedmann equation (1) (a) (3 points) By referring to the Friedmann equation 1), derive an equation for a static Universe when k -0 (b) (8 points) Last week you derived an...
Newtonian Cosmology 1. In class, we solved the Friedmann equation for the critical case, where the constant of integration was set to k 0; this resulted in the Einstein-de Sitter model, where a ox t2/3 Now, let us consider the closed case (k 1), where the universe starts with a Big Bang, reaches a maximum expansion, turns around, and eventually ends in a Big Crunch. For the closed model, it is convenient to write the Friedmann equation as follows: 8T...
2. (i)Describe with neat sketches the meanings of streamlines, pathlines and streaklines. (6 marks) (Gi) Derive the equation of the streamlines for the following flow field and sketch them. (4 marks) (iii) A flow field is given as (a) Determine the z-component of velocity assuming the flow field is for an incompressible fluid. (4 marks) (b) Determine the velocity and acceleration at the point (1,2,3) at time t-1. (6 marks) Assume that the z-component of velocity at z-0 is zero....
2.) As a raindrop falls through a cloud, it collides with smaller droplets of mist and grows in mass (a) Derive a differential equation that relates the mass and velocity of the drop as it falls and accretes mass. Hint: Do NOT just differentiate d(mv)/dt, but start with the impulse-momentum theorem in differential form, like we did in the derivation of the rocket equation. Your "system" should include the raindrop itself and a small mass Δm of droplets with which...
I need help with exercise #2. Your help will be really
appreciated and rated.
MAXWELL'S EQUATION I. Maxwell's Equation: Our first (of mony) distribution functions. Very important A. The "Maxwell-Boltzman speed distribution" gives the speed distribution, fiv), of particles confined to NN()d, which a volume, V, and in thermal equilibrium at a temperature, T. () is the number of particles moving within dv of a speed, v Distributions of this type can be considered as the product of three terms...
Elementary Differential Equation Unit Step Function Problem
Project 2 A Spring-Mass Event Problenm A mass of magnitude m is confined to one-dimensional motion between two springs on a frictionless horizontal surface, as shown in Figure 4.P.3. The mass, which is unattached to either spring, undergoes simple inertial motion whenever the distance from the origin of the center point of the mass, x, satisfies lxl < L. When x 2 L, the mass is in contact with the spring on the...