Problem 2 Calculate the electron scattering rate, t, the mean free path A, the electrical conductivity...
Problem 4: The mean free path of a gas, 2, is defined as the average distance traveled by molecules between collisions. A commonly used formula for estimating 2 of an ideal gas is: where џ is the viscosity of the gas, is the density of air. T is the temperature in Kelvin, and C is an experimentally determined constant. Calculate the mean free path of air (in units of nm) at 25 °C and standard atmospheric pressure if the viscosity...
Question 3.1 The differential cross-section of the coherent scattering intensity for a free electron is expressed by the following equation with respect to per unit plane angle (radian), if the classical electron radius is set to r. os20) 2n sin (m²/rad) (1) Estimate me which is called the Thomson classical scattering coefficient by the integration about angle. (2) Express the Thomson classical scattering coefficient in barn unit. (1barn = 1 x 10-28 m²). (3) When X-rays penetrate an aluminum foil...
2-157 A long electrical resistance wire of radius r.-0.25 cm has a thermal conductivity kwire-15 W/m-K. Heat is generated uniformly in the wire as a result of resistance heating at a constant rate of 0.5 W/cm3. The wire is covered with polyethylene insulation with a thickness of 0.25 cm and thermal conductivity of ks 0.4 W/m K. The outer surface of the insulation is subjected to free convection in air at 20°C and a convection heat transfer coefficient of 2...
Problem 2. Find the mean free path of nitrogen gas at pressure p = 2.5 atm and temperature T = 56.5°F. The diameter of a nitrogen molecule is d= 0.3 nm. What is the average rate of collisions?
5. Problem 3.54 (Textbook) (20 points) KNOWN: Diameter of electrical wire. Thickness and thermal conductivity of rubberized sheath. Contact resistance between sheath and wire. Convection coefficient and ambient air temperature. Maximum allowable sheath temperature. FIND: Maximum allowable power dissipation per unit length of wire. Critical radius of insulation. SCHEMATIC: Air Wire Egen. D-2 mm Two Tini Tino To Ric = 3x10-4 m2-KW Insulation, t = 2 mm T= 20°C Ric Rcond conv k = 0.13 W/m-K Tmax = 50°C h...
Problem 3 - Mean free path (8 marks) Let's assume the opacity inside of a star is constant. The optical depth is T = not where o is the collisional cross-section of an ion. If the optical depth is T = 1, then the photon can't go very far before it's scattered. We write the mean free path as L which is the average distance a photon can go before being scattered. a. If the conditions in the Sun have...
please help solve Use the pre-lab data to calculate the thermal conductivity of the Aluminum sample measured in a composite wall experiment. Mid-section material: Aluminum Ambient temperature: 27°C T.(°C) Tz(°C) Power(W) 96.1 84.5 43.0 T3(°C) T(C) Ts(°C) T.(°C) T (°C) 72.9 62. 6 52.2 41.6 30.6 Distance 0.0 0.02 0.04 0.06 0.08 0.10 0.12 from T(m) PAGE: Given Data o Thermal conductivity of the brass (type CZ121) is 123 W/m.K o Thermal convection of air is 20 W/ m K...
LT An aluminum rod of diameter D 2.5 cm and of length from a wall maintained at T, 300"C. The.coovective heat coefficient h 17 W/m2-K with an ambie.t air temperature T Thermal conductivity k = 204 WmK. Assume there is e luid by convection from the end of the rod, which is at temperature Ta. Using 2. -38c. nergy transfer to the a finite difference method, with Ax = 5 cm, the fo be derived for the solution of the...
Fermi Energy Eqn. 4.22 in Kasap gives the Fermi energy (at 0 K) as is the conduction electron concentration. This is equivalent to the equation we derived in class. Kasap Eqn. 4.23 gives the Fermi energy as a function of temperature: EFEF1 a. If each copper atom contributes one conduction electron, what is the Fermi energy of copper at 29:3 b. Since this Fermi energy was derived from the Sommerfeld model, the energy is entirely kinetic 12 LEFo K? energy...
Calculate the mean free path of air molecules at a pressure of 4.50×10−13 atm and a temperature of 292 K. (This pressure is readily attainable in the laboratory.) Model the air molecules as spheres with a radius of 2.00×10−10 m. λλ = m