College Physics
1st Edition
ISBN: 9781938168000
Author: Paul Peter Urone, Roger Hinrichs
Publisher: OpenStax College
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 23, Problem 39PE
Suppose a motor connected to a 120 V source draws 10.0 A when it first starts. (a) What is its resistance? (b) What current does it draw at its normal operating speed when it develops a 100 V back emf?
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
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…
SECTION 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]
Page 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)…
Chapter 23 Solutions
College Physics
Ch. 23 - How do the multiple-loop coils and iron ring in...Ch. 23 - When a magnet is thrust into a coil as in Figure...Ch. 23 - Explain how magnetic flux can be zero when the...Ch. 23 - Is an emf induced in the coil in Figure 23.54 when...Ch. 23 - A person who works with large magnets sometimes...Ch. 23 - A particle accelerator sends highvelocity charged...Ch. 23 - Why must pan of the circuit be moving relative to...Ch. 23 - A powerful induction cannon can be made by placing...Ch. 23 - An induction slave heats a pot with a coil...Ch. 23 - Explain how you could thaw out a frozen water pipe...
Ch. 23 - Explain why magnetic damping might not be...Ch. 23 - Explain how electromagnetic induction can be used...Ch. 23 - Using RHR-l, show that the emfs in the sides of...Ch. 23 - The source of a generator’s electrical energy...Ch. 23 - Suppose you find that the belt drive connecting a...Ch. 23 - Explain what causes physical vibrations in...Ch. 23 - Does plastic insulation on live/hot wires prevent...Ch. 23 - Why are ordinary circuit breakers and fuses...Ch. 23 - A GFI may trip just because the live/hot and...Ch. 23 - How would you place two identical flat coils in...Ch. 23 - How would you shape a given length of wire to give...Ch. 23 - €22. Verify, as was concluded without proof in...Ch. 23 - Presbycusis is a hearing loss due to age that...Ch. 23 - Would you use a large inductance or a large...Ch. 23 - High-frequency noise in AC power can damage...Ch. 23 - Does inductance depend on current, frequency, or...Ch. 23 - Explain why the capacitor in Figure 23.55(a) acts...Ch. 23 - If the capacitors in Figure 23.55 are replaced by...Ch. 23 - Does the resonant frequency of an AC circuit...Ch. 23 - Suppose you have a motor with a power factor...Ch. 23 - What is the value of the magnetic flux at coil 2...Ch. 23 - What is the value of the magnetic flux through the...Ch. 23 - Referring to Figure 23.5?(a), what is the...Ch. 23 - Referring to Figure 23.57(b), what is the...Ch. 23 - Referring to Figure 23.58, what are the directions...Ch. 23 - Repeat the previous problem with the battery...Ch. 23 - Verify that the units /t are volts. That is, show...Ch. 23 - Suppose a 50-turn coil lies in the plane of the...Ch. 23 - (a) An MRI technician moves his hand from a region...Ch. 23 - Integrated Concepts Referring to the situation in...Ch. 23 - An emf is induced by rotating a 1000-turn, 20.0 cm...Ch. 23 - A 0.250 m radius, 500-turn coil is rotated...Ch. 23 - Integrated Concepts Approximately how does the emf...Ch. 23 - Integrated Concepts A lightning bolt produces a...Ch. 23 - Use Faraday’s law, Lenz’s law, and RHR—l to show...Ch. 23 - If a current flows in the Satellite Tether shown...Ch. 23 - (a) A jet airplane with a 75.0 m wingspan is...Ch. 23 - (a) A nonferrous screwdriver is being used in a...Ch. 23 - At what speed must the sliding rod in Figure 23.11...Ch. 23 - The 12.0 cm long rod in Figure 23.11 moves at 4.00...Ch. 23 - Prove that when B, l, and v are not mutually...Ch. 23 - In the August 1992 space shuttle flight, only 250...Ch. 23 - Integrated Concepts Derive an expression for the...Ch. 23 - Integrated Concepts The Tethered Satellite in...Ch. 23 - Integrated Concepts The Tethered Satellite...Ch. 23 - Make a drawing similar to Figure 23.14, but with...Ch. 23 - Figure 23.59 A coil is moved into and out of a...Ch. 23 - Calculate the peak voltage of a generator that...Ch. 23 - At what angular velocity in rpm will the peak...Ch. 23 - What is the peak emf generated by rotating a...Ch. 23 - What is the peak emf generated by a 0.250 m...Ch. 23 - (a) A bicycle generator rotates at 1875 rad/s,...Ch. 23 - Integrated Concepts This problem refers to the...Ch. 23 - (a) A car generator turns at 400 rpm when 1he...Ch. 23 - Show that if a coil rotates at an angular velocity...Ch. 23 - A 75-turn, 10.0 cm diameter coil rotates at an...Ch. 23 - (a) If the emf of a coil rotating in a magnetic...Ch. 23 - Unreasonable Results A 500-turn coil with a 0.250...Ch. 23 - Suppose a motor connected to a 120 V source draws...Ch. 23 - A motor operating on 240 V electricity has a 180 V...Ch. 23 - What is the back emf of a 120 V motor that draws...Ch. 23 - The motor in a toy car operates on 6.00 V....Ch. 23 - Integrated Concepts The motor in a toy car is...Ch. 23 - A plug—in transformer, like that in Figure 23.29,...Ch. 23 - An American traveler in New Zealand carries a...Ch. 23 - A cassette recorder uses a plug-in transformer to...Ch. 23 - (a) What is the voltage output of a transformer...Ch. 23 - (a) The plug-in transformer for a laptop computer...Ch. 23 - A multipurpose transformer has a secondary coil...Ch. 23 - A large power plant generates electricity at 12.0...Ch. 23 - If the power output in the previous problem is...Ch. 23 - Unreasonable Results The 335 kV AC electricity...Ch. 23 - Construct Your Own Problem Consider a double...Ch. 23 - Integrated Concepts A short circuit to the...Ch. 23 - Two coils are placed close together in a physics...Ch. 23 - If two coils placed next to one another have a...Ch. 23 - The 4.00 A current through a 7.50 mH inductor is...Ch. 23 - A device is turned on and 3.00 A flows through it...Ch. 23 - Starting with emf2=MI1t, show that the units of...Ch. 23 - Camera flashes charge a capacitor to high voltage...Ch. 23 - A large research solenoid has a self-inductance of...Ch. 23 - (a) Calculate the self-inductance of a 50.0 cm...Ch. 23 - A precision laboratory resistor is made of a coil...Ch. 23 - The healing coils in a hair dryer are 0.800 cm in...Ch. 23 - When the 20.0 A current through an inductor is...Ch. 23 - How fast can the 150 A current through a 0.250 H...Ch. 23 - Integrated Concepts A very large, superconducting...Ch. 23 - Unreasonable Results A 25.0 H inductor has 100 A...Ch. 23 - It you want a characteristic RL time constant of...Ch. 23 - Your RL circuit has a characteristic time constant...Ch. 23 - A large superconducting magnet, used for magnetic...Ch. 23 - Verify that alter a time of 10.0 ms, the current...Ch. 23 - Suppose you have a supply of inductors ranging...Ch. 23 - (a) What is the characteristic time constant of a...Ch. 23 - What percentage of the final current I0 flows...Ch. 23 - The 5.00 A current through a 1.50 H inductor is...Ch. 23 - (a) Use the exact exponential treatment to find...Ch. 23 - (a) Using the exact exponential treatment, find...Ch. 23 - At what frequency will a 30.0 mH inductor have a...Ch. 23 - What value of inductance should be used if a 20.0...Ch. 23 - What capacitance should be used to produce a 2.00...Ch. 23 - At what frequency will an 80.0 mF capacitor have a...Ch. 23 - (a) Find me current through a 0.500 H inductor...Ch. 23 - (a) What current flows when a 60.0 Hz, 480 V AC...Ch. 23 - A 20.0 kHz, 16.0 V source connected to an inductor...Ch. 23 - A 20.0 HZ, 16.0 V source produces a 2.00 mA...Ch. 23 - (a) An inductor designed to filter high-frequency...Ch. 23 - The capacitor in Figure 23.55(a) is designed to...Ch. 23 - The capacitor in Figure 23.55(b) will filler...Ch. 23 - Unreasonable Results In a recording of voltages...Ch. 23 - Construct Your Own Problem Consider the use of an...Ch. 23 - An RL circuit consists of a 40.0 (resistor and a...Ch. 23 - An RC circuit consists of a 40.0 (resistor and a...Ch. 23 - An LC circuit consists of a 3.00 mH inductor and a...Ch. 23 - What is the resonant frequency of a 0.500 mH...Ch. 23 - To receive AM radio, you want an RLC circuit that...Ch. 23 - Suppose you have a supply of inductors ranging...Ch. 23 - What capacitance do you need to produce a resonant...Ch. 23 - What inductance do you need to produce a resonant...Ch. 23 - The lowest frequency in the FM radio band is 88.0...Ch. 23 - An RLC series circuit has a 2.50 (resistor, a 100...Ch. 23 - An RLC series circuit hag a 1.00 k(register, a 150...Ch. 23 - An RLC series circuit has a 2.50 (resistor, a 100...Ch. 23 - An RLC series circuit has a 1.00 k(resistor, a...Ch. 23 - An RLC series circuit has a 200 (resistor and a...Ch. 23 - Referring to Example 23.14, find the average power...
Additional Science Textbook Solutions
Find more solutions based on key concepts
1. An object is subject to two forces that do not point in opposite directions. Is it possible to choose their ...
College Physics: A Strategic Approach (3rd Edition)
Raw Oysters and Antacids: A Deadly Mix? The highly acidic environment of the stomach kills most bacteria before...
Microbiology with Diseases by Body System (5th Edition)
Match the people in column A to their contribution toward the advancement of microbiology, in column B. Column ...
Microbiology: An Introduction
17. Anthropologists are interested in locating areas in Africa where fossils 4-8 million years old might be fou...
Campbell Biology: Concepts & Connections (9th Edition)
Police Captain Jeffers has suffered a myocardial infarction. a. Explain to his (nonmedically oriented) family w...
Human Physiology: An Integrated Approach (8th Edition)
25. The 100 kg block in FIGURE EX7.25 takes 6.0 s to reach the floor after being released from rest. What is th...
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- 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
- What is integrated science. What is fractional distillation What is simple distillationarrow_forward19:39 · C Chegg 1 69% ✓ The compound beam is fixed at Ę and supported by rollers at A and B. There are pins at C and D. Take F=1700 lb. (Figure 1) Figure 800 lb ||-5- F 600 lb بتا D E C BO 10 ft 5 ft 4 ft-—— 6 ft — 5 ft- Solved Part A The compound beam is fixed at E and... Hình ảnh có thể có bản quyền. Tìm hiểu thêm Problem A-12 % Chia sẻ kip 800 lb Truy cập ) D Lưu of C 600 lb |-sa+ 10ft 5ft 4ft6ft D E 5 ft- Trying Cheaa Những kết quả này có hữu ích không? There are pins at C and D To F-1200 Egue!) Chegg Solved The compound b... Có Không ☑ ||| Chegg 10 וחarrow_forwardNo chatgpt pls will upvotearrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College
Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-Hill
Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781938168000
Author:Paul Peter Urone, Roger Hinrichs
Publisher:OpenStax College
Glencoe Physics: Principles and Problems, Student...
Physics
ISBN:9780078807213
Author:Paul W. Zitzewitz
Publisher:Glencoe/McGraw-Hill
Physics for Scientists and Engineers, Technology ...
Physics
ISBN:9781305116399
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
What is Electromagnetic Induction? | Faraday's Laws and Lenz Law | iKen | iKen Edu | iKen App; Author: Iken Edu;https://www.youtube.com/watch?v=3HyORmBip-w;License: Standard YouTube License, CC-BY