Concept explainers
You are working as an expert witness in a civil case. You have been hired by the attorney for a company that manufactures compasses. The company is being sued by a novice hiker who used one of the company’s top-level compasses. The hiker claims that the compass was defective, sending him off in a different direction from his desired direction. After taking off in the erroneous direction, he dropped and lost his compass so that he could not take subsequent measurements. As a result, he became lost for days, with the subsequent ill effects on his health and lost wages from missed days at work. The hiker has provided the exact location at which he took the erroneous compass reading. You take a trip to this location and look around. You notice that there is an electric power transmission line directly above sour location, running in a north–south direction. Using trigonometry, you determine that the power line is a vertical distance of 6.65 m above the ground. Upon returning to your office, you contact employees of the electric power company, who tell you that that particular rural power line actually carries DC current with a typical magnitude during the day of 135 A. (a) In order to provide advice in this case, you calculate the magnetic field caused by the power line at the location of the hiker. (b) What advice do you give to the attorney?
Want to see the full answer?
Check out a sample textbook solutionChapter 29 Solutions
Bundle: Physics for Scientists and Engineers with Modern Physics, Loose-leaf Version, 10th + WebAssign Printed Access Card for Serway/Jewett's Physics for Scientists and Engineers, 10th, Multi-Term
- Question B3 Consider the following FLRW spacetime: t2 ds² = -dt² + (dx² + dy²+ dz²), t2 where t is a constant. a) State whether this universe is spatially open, closed or flat. [2 marks] b) Determine the Hubble factor H(t), and represent it in a (roughly drawn) plot as a function of time t, starting at t = 0. [3 marks] c) Taking galaxy A to be located at (x, y, z) = (0,0,0), determine the proper distance to galaxy B located at (x, y, z) = (L, 0, 0). Determine the recessional velocity of galaxy B with respect to galaxy A. d) The Friedmann equations are 2 k 8πG а 4πG + a² (p+3p). 3 a 3 [5 marks] Use these equations to determine the energy density p(t) and the pressure p(t) for the FLRW spacetime specified at the top of the page. [5 marks] e) Given the result of question B3.d, state whether the FLRW universe in question is (i) radiation-dominated, (ii) matter-dominated, (iii) cosmological-constant-dominated, or (iv) none of the previous. Justify your answer. f) [5 marks] A conformally…arrow_forwardSECTION B Answer ONLY TWO questions in Section B [Expect to use one single-sided A4 page for each Section-B sub question.] Question B1 Consider the line element where w is a constant. ds²=-dt²+e2wt dx², a) Determine the components of the metric and of the inverse metric. [2 marks] b) Determine the Christoffel symbols. [See the Appendix of this document.] [10 marks] c) Write down the geodesic equations. [5 marks] d) Show that e2wt it is a constant of geodesic motion. [4 marks] e) Solve the geodesic equations for null geodesics. [4 marks]arrow_forwardPage 2 SECTION A Answer ALL questions in Section A [Expect to use one single-sided A4 page for each Section-A sub question.] Question A1 SPA6308 (2024) Consider Minkowski spacetime in Cartesian coordinates th = (t, x, y, z), such that ds² = dt² + dx² + dy² + dz². (a) Consider the vector with components V" = (1,-1,0,0). Determine V and V. V. (b) Consider now the coordinate system x' (u, v, y, z) such that u =t-x, v=t+x. [2 marks] Write down the line element, the metric, the Christoffel symbols and the Riemann curvature tensor in the new coordinates. [See the Appendix of this document.] [5 marks] (c) Determine V", that is, write the object in question A1.a in the coordinate system x'. Verify explicitly that V. V is invariant under the coordinate transformation. Question A2 [5 marks] Suppose that A, is a covector field, and consider the object Fv=AAμ. (a) Show explicitly that F is a tensor, that is, show that it transforms appropriately under a coordinate transformation. [5 marks] (b)…arrow_forward
- No chatgpt pls will upvote Iarrow_forwardHow would partial obstruction of an air intake port of an air-entrainment mask effect FiO2 and flow?arrow_forward14 Z In figure, a closed surface with q=b= 0.4m/ C = 0.6m if the left edge of the closed surface at position X=a, if E is non-uniform and is given by € = (3 + 2x²) ŷ N/C, calculate the (3+2x²) net electric flux leaving the closed surface.arrow_forward
- No chatgpt pls will upvotearrow_forwardsuggest a reason ultrasound cleaning is better than cleaning by hand?arrow_forwardCheckpoint 4 The figure shows four orientations of an electric di- pole in an external electric field. Rank the orienta- tions according to (a) the magnitude of the torque on the dipole and (b) the potential energy of the di- pole, greatest first. (1) (2) E (4)arrow_forward
- Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-HillPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning
- College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax CollegePrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning