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Does the uncharged conductor shown below experience a net electric force?

A sphere is shown suspended by a thread from the ceiling. A negatively charged rod is brought near the sphere.

Yes, polarization charge is induced on the conductor so that the positive charge is nearest the charged rod, causing an attractive force.

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While walking on a rug, a person frequently becomes charged because of the rubbing between his shoes and the rug. This charge then causes a spark and a slight shock when the person gets close to a metal object. Why are these shocks so much more common on a dry day?

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Compare charging by conduction to charging by induction.

Charging by conduction is charging by contact where charge is transferred to the object. Charging by induction first involves producing a polarization charge in the object and then connecting a wire to ground to allow some of the charge to leave the object, leaving the object charged.

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Small pieces of tissue are attracted to a charged comb. Soon after sticking to the comb, the pieces of tissue are repelled from it. Explain.

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Trucks that carry gasoline often have chains dangling from their undercarriages and brushing the ground. Why?

This is so that any excess charge is transferred to the ground, keeping the gasoline receptacles neutral. If there is excess charge on the gasoline receptacle, a spark could ignite it.

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Why do electrostatic experiments work so poorly in humid weather?

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Why do some clothes cling together after being removed from the clothes dryer? Does this happen if they’re still damp?

The dryer charges the clothes. If they are damp, the presence of water molecules suppresses the charge.

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Can induction be used to produce charge on an insulator?

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Suppose someone tells you that rubbing quartz with cotton cloth produces a third kind of charge on the quartz. Describe what you might do to test this claim.

There are only two types of charge, attractive and repulsive. If you bring a charged object near the quartz, only one of these two effects will happen, proving there is not a third kind of charge.

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A handheld copper rod does not acquire a charge when you rub it with a cloth. Explain why.

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Suppose you place a charge q near a large metal plate. (a) If q is attracted to the plate, is the plate necessarily charged? (b) If q is repelled by the plate, is the plate necessarily charged?

a. No, since a polarization charge is induced. b. Yes, since the polarization charge would produce only an attractive force.

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Problems

Suppose a speck of dust in an electrostatic precipitator has 1.0000 × 10 12 protons in it and has a net charge of −5.00 nC (a very large charge for a small speck). How many electrons does it have?

5.00 × 10 −9 C ( 6.242 × 10 18 e / C ) = 3.121 × 10 19 e ;
3.121 × 10 19 e + 1.0000 × 10 12 e = 3.1210001 × 10 19 e

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An amoeba has 1.00 × 10 16 protons and a net charge of 0.300 pC. (a) How many fewer electrons are there than protons? (b) If you paired them up, what fraction of the protons would have no electrons?

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A 50.0-g ball of copper has a net charge of 2.00 μ C . What fraction of the copper’s electrons has been removed? (Each copper atom has 29 protons, and copper has an atomic mass of 63.5.)

atomic mass of copper atom times 1 u = 1.055 × 10 −25 kg ;
number of copper atoms = 4.739 × 10 23 atoms ;
number of electrons equals 29 times number of atoms or 1.374 × 10 25 electrons ; 2.00 × 10 −6 C ( 6.242 × 10 18 e / C ) 1.374 × 10 25 e = 9.083 × 10 −13 or 9.083 × 10 −11 %

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What net charge would you place on a 100-g piece of sulfur if you put an extra electron on 1 in 10 12 of its atoms? (Sulfur has an atomic mass of 32.1 u.)

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How many coulombs of positive charge are there in 4.00 kg of plutonium, given its atomic mass is 244 and that each plutonium atom has 94 protons?

244.00 u ( 1.66 × 10 −27 kg / u ) = 4.050 × 10 −25 kg ;
4.00 kg 4.050 × 10 −25 kg = 9.877 × 10 24 atoms 9.877 × 10 24 ( 94 ) = 9.284 × 10 26 protons ;
9.284 × 10 26 ( 1.602 × 10 −19 C / p ) = 1.487 × 10 8 C

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Questions & Answers

A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
Aislinn Reply
cm
tijani
what is titration
John Reply
what is physics
Siyaka Reply
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance
Jude Reply
Can you compute that for me. Ty
Jude
what is the dimension formula of energy?
David Reply
what is viscosity?
David
what is inorganic
emma Reply
what is chemistry
Youesf Reply
what is inorganic
emma
Chemistry is a branch of science that deals with the study of matter,it composition,it structure and the changes it undergoes
Adjei
please, I'm a physics student and I need help in physics
Adjanou
chemistry could also be understood like the sexual attraction/repulsion of the male and female elements. the reaction varies depending on the energy differences of each given gender. + masculine -female.
Pedro
A ball is thrown straight up.it passes a 2.0m high window 7.50 m off the ground on it path up and takes 1.30 s to go past the window.what was the ball initial velocity
Krampah Reply
2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
Sahid Reply
you have been hired as an espert witness in a court case involving an automobile accident. the accident involved car A of mass 1500kg which crashed into stationary car B of mass 1100kg. the driver of car A applied his brakes 15 m before he skidded and crashed into car B. after the collision, car A s
Samuel Reply
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
Joseph Reply
Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
Joseph
"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
Ryan
what's motion
Maurice Reply
what are the types of wave
Maurice
answer
Magreth
progressive wave
Magreth
hello friend how are you
Muhammad Reply
fine, how about you?
Mohammed
hi
Mujahid
A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?
yasuo Reply
Who can show me the full solution in this problem?
Reofrir Reply
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Source:  OpenStax, University physics volume 2. OpenStax CNX. Oct 06, 2016 Download for free at http://cnx.org/content/col12074/1.3
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