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Physics for Scientists and Engineers with Modern Physics
4th Edition
ISBN: 9780131495081
Author: Douglas C. Giancoli
Publisher: Addison-Wesley
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Question
Chapter 29, Problem 41P
To determine
The back emf of the motor at
Expert Solution & Answer
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Students have asked these similar questions
1)
Consider two positively charged particles, one of charge q0 (particle 0) fixed at the origin, and another of charge q1 (particle 1) fixed on the y-axis at (0,d1,0). What is the net force F→ on particle 0 due to particle 1?
Express your answer (a vector) using any or all of k, q0, q1, d1, i^, j^, and k^.
2)
Now add a third, negatively charged, particle, whose charge is −q2− (particle 2). Particle 2 fixed on the y-axis at position (0,d2,0). What is the new net force on particle 0, from particle 1 and particle 2?
Express your answer (a vector) using any or all of k, q0, q1, q2, d1, d2, i^, j^, and k^.
3)
Particle 0 experiences a repulsion from particle 1 and an attraction toward particle 2. For certain values of d1 and d2, the repulsion and attraction should balance each other, resulting in no net force. For what ratio d1/d2 is there no net force on particle 0?
Express your answer in terms of any or all of the following variables: k, q0, q1, q2.
A 85 turn, 10.0 cm diameter coil rotates at an angular velocity of 8.00 rad/s in a 1.35 T field, starting with the normal of the plane of the coil perpendicular to the field. Assume that the positive max emf is reached first.
(a) What (in V) is the peak emf?
7.17
V
(b) At what time (in s) is the peak emf first reached?
0.196
S
(c) At what time (in s) is the emf first at its most negative?
0.589
x s
(d) What is the period (in s) of the AC voltage output?
0.785
S
A bobsled starts at the top of a track as human runners sprint from rest and then jump into the sled. Assume they reach 40 km/h from rest after covering a distance of 50 m over flat ice. a. How much work do they do on themselves and the sled which they are pushing given the fact that there are two men of combined mass 185 kg and the sled with a mass of 200 kg? (If you haven't seen bobsledding, watch youtube to understand better what's going on.) b. After this start, the team races down the track and descends vertically by 200 m. At the finish line the sled crosses with a speed of 55 m/s. How much energy was lost to drag and friction along the way down after the men were in the sled?
Chapter 29 Solutions
Physics for Scientists and Engineers with Modern Physics
Ch. 29.1 - Return to the Chapter-Opening Question, page 758,...Ch. 29.2 - Prob. 1BECh. 29.3 - In what direction will the electrons now in Fig....Ch. 29.5 - A bicycle headlight is powered by a generator that...Ch. 29.7 - Prob. 1EECh. 29 - Prob. 1QCh. 29 - What is the difference between magnetic flux and...Ch. 29 - Suppose you are holding a circular ring of wire...Ch. 29 - Prob. 4QCh. 29 - Is there a force between the two loops discussed...
Ch. 29 - Suppose you are looking along a line through the...Ch. 29 - The battery mentioned in Question 6 is...Ch. 29 - Prob. 8QCh. 29 - Prob. 9QCh. 29 - In situations where a small signal must travel...Ch. 29 - What is the advantage of placing the two insulated...Ch. 29 - Prob. 12QCh. 29 - A region where no magnetic field is desired is...Ch. 29 - A cell phone charger contains a transformer. Why...Ch. 29 - An enclosed transformer has four wire leads coming...Ch. 29 - The use of higher-voltage lines in homessay, 600 V...Ch. 29 - Prob. 17QCh. 29 - Prob. 18QCh. 29 - Prob. 19QCh. 29 - Will an eddy current brake (Fig. 2921) work on a...Ch. 29 - It has been proposed that eddy currents be used to...Ch. 29 - The pivoted metal bar with slots in Fig. 2935...Ch. 29 - If an aluminum sheet is held between the poles of...Ch. 29 - A bar magnet falling inside a vertical metal tube...Ch. 29 - A metal bar, pivoted at one end, oscillates freely...Ch. 29 - Since a magnetic microphone is basically like a...Ch. 29 - Prob. 1PCh. 29 - (I) The north pole of the magnet in Fig. 2936 is...Ch. 29 - Prob. 3PCh. 29 - (I) A 22.0-cm-diameter loop of wire is initially...Ch. 29 - Prob. 5PCh. 29 - (II) A 10.8-cm-diameter wire coil is initially...Ch. 29 - (II) A 16-cm-diameter circular loop of wire is...Ch. 29 - (II) (a) If the resistance of the resistor in Fig....Ch. 29 - Prob. 9PCh. 29 - (II) The magnetic field perpendicular to a...Ch. 29 - (II) A circular loop in the plane of the paper...Ch. 29 - (II) Part of a single rectangular loop of wire...Ch. 29 - (II) While demonstrating Faradays law to her...Ch. 29 - Prob. 14PCh. 29 - (II) A 22.0-cm-diameter coil consists of 28 turns...Ch. 29 - (II) A power line carrying a sinusoidally varying...Ch. 29 - (II) The magnetic field perpendicular to a single...Ch. 29 - Prob. 18PCh. 29 - (II) A 25-cm-diameter circular loop of wire has a...Ch. 29 - (II) The area of an elastic circular loop...Ch. 29 - Prob. 21PCh. 29 - Prob. 22PCh. 29 - Prob. 23PCh. 29 - (II) Inductive battery chargers, which allow...Ch. 29 - Prob. 25PCh. 29 - Prob. 26PCh. 29 - (I) The moving rod in Fig. 2912b is 13.2 cm long...Ch. 29 - (I) The moving rod in Fig. 2912b is 12.0 cm long...Ch. 29 - Prob. 29PCh. 29 - (II) If the U-shaped conductor in Fig. 2912a has...Ch. 29 - (II) Suppose that the U-shaped conductor and...Ch. 29 - (II) When a car drives through the Earths magnetic...Ch. 29 - Prob. 33PCh. 29 - Prob. 34PCh. 29 - (III) A short section of wire, of length a, is...Ch. 29 - (I) The generator of a car idling at 875-rpm...Ch. 29 - Prob. 37PCh. 29 - (II) A simple generator has a 480-loop square coil...Ch. 29 - (II) Show that the rms output of an ac generator...Ch. 29 - (II) A 250-loop circular armature coil with a...Ch. 29 - Prob. 41PCh. 29 - (I) A motor has an armature resistance of 3.05 ....Ch. 29 - (II) What will be the current in the motor of...Ch. 29 - (II) The back emf in a motor is 85 V when the...Ch. 29 - Prob. 45PCh. 29 - (I) A transformer has 620 turns in the primary...Ch. 29 - (I) Neon signs require 12 kV for their operation....Ch. 29 - (II) A model-train transformer plugs into 120-V ac...Ch. 29 - (II) The output voltage of a 75-W transformer is...Ch. 29 - (II) If 65 MW of power at 45 kV (rms) arrives at a...Ch. 29 - Prob. 51PCh. 29 - (III) Design a dc transmission line that can...Ch. 29 - (III) Suppose 85 kW is to be transmitted over two...Ch. 29 - Prob. 54PCh. 29 - (II) The betatron, a device used to accelerate...Ch. 29 - (III) Show that the electrons in a betatron,...Ch. 29 - (III) Find a formula for the net electric field in...Ch. 29 - Prob. 58GPCh. 29 - A square loop 27.0 cm on a side has a resistance...Ch. 29 - Power is generated at 24 kV at a generating plant...Ch. 29 - Prob. 61GPCh. 29 - Prob. 62GPCh. 29 - A pair of power transmission lines each have a...Ch. 29 - Show that the power loss in transmission lines,...Ch. 29 - A high-intensity desk lamp is rated at 35 W but...Ch. 29 - Prob. 66GPCh. 29 - A coil with 150 turns, a radius of 5.0 cm, and a...Ch. 29 - A search coil for measuring B (also called a flip...Ch. 29 - A ring with a radius of 3.0 cm and a resistance of...Ch. 29 - A flashlight can be made that is powered by the...Ch. 29 - A small electric car overcomes a 250-N friction...Ch. 29 - What is the energy dissipated as a function of...Ch. 29 - A thin metal rod of length rotates with angular...Ch. 29 - The magnetic field of a shunt-wound dc motor is...Ch. 29 - Prob. 75GPCh. 29 - A circular metal disk of radius R rotates with...Ch. 29 - What is the magnitude and direction of the...Ch. 29 - Prob. 78GPCh. 29 - Prob. 79GPCh. 29 - Prob. 80GP
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