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190-193
(1 1) Coulomb thought of the following simple way: Suppose the charge on a metallic sphere is q If the sphere is put in contact with an identical uncharged sphere, the charge will spread over the two spheres
1
191-194
1) Coulomb thought of the following simple way: Suppose the charge on a metallic sphere is q If the sphere is put in contact with an identical uncharged sphere, the charge will spread over the two spheres By symmetry, the charge on each sphere will be q/2*
1
192-195
Coulomb thought of the following simple way: Suppose the charge on a metallic sphere is q If the sphere is put in contact with an identical uncharged sphere, the charge will spread over the two spheres By symmetry, the charge on each sphere will be q/2* Repeating this process, we can get charges q/2, q/4, etc
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193-196
If the sphere is put in contact with an identical uncharged sphere, the charge will spread over the two spheres By symmetry, the charge on each sphere will be q/2* Repeating this process, we can get charges q/2, q/4, etc Coulomb varied the distance for a fixed pair of charges and measured the force for different separations
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194-197
By symmetry, the charge on each sphere will be q/2* Repeating this process, we can get charges q/2, q/4, etc Coulomb varied the distance for a fixed pair of charges and measured the force for different separations He then varied the charges in pairs, keeping the distance fixed for each pair
1
195-198
Repeating this process, we can get charges q/2, q/4, etc Coulomb varied the distance for a fixed pair of charges and measured the force for different separations He then varied the charges in pairs, keeping the distance fixed for each pair Comparing forces for different pairs of charges at different distances, Coulomb arrived at the relation, Eq
1
196-199
Coulomb varied the distance for a fixed pair of charges and measured the force for different separations He then varied the charges in pairs, keeping the distance fixed for each pair Comparing forces for different pairs of charges at different distances, Coulomb arrived at the relation, Eq (1
1
197-200
He then varied the charges in pairs, keeping the distance fixed for each pair Comparing forces for different pairs of charges at different distances, Coulomb arrived at the relation, Eq (1 1)
1
198-201
Comparing forces for different pairs of charges at different distances, Coulomb arrived at the relation, Eq (1 1) Coulomb’s law, a simple mathematical statement, was initially experimentally arrived at in the manner described above
1
199-202
(1 1) Coulomb’s law, a simple mathematical statement, was initially experimentally arrived at in the manner described above While the original experiments established it at a macroscopic scale, it has also been established down to subatomic level (r ~ 10–10 m)
1
200-203
1) Coulomb’s law, a simple mathematical statement, was initially experimentally arrived at in the manner described above While the original experiments established it at a macroscopic scale, it has also been established down to subatomic level (r ~ 10–10 m) Coulomb discovered his law without knowing the explicit magnitude of the charge
1
201-204
Coulomb’s law, a simple mathematical statement, was initially experimentally arrived at in the manner described above While the original experiments established it at a macroscopic scale, it has also been established down to subatomic level (r ~ 10–10 m) Coulomb discovered his law without knowing the explicit magnitude of the charge In fact, it is the other way round: Coulomb’s law can now be employed to furnish a definition for a unit of charge
1
202-205
While the original experiments established it at a macroscopic scale, it has also been established down to subatomic level (r ~ 10–10 m) Coulomb discovered his law without knowing the explicit magnitude of the charge In fact, it is the other way round: Coulomb’s law can now be employed to furnish a definition for a unit of charge In the relation, Eq
1
203-206
Coulomb discovered his law without knowing the explicit magnitude of the charge In fact, it is the other way round: Coulomb’s law can now be employed to furnish a definition for a unit of charge In the relation, Eq (1
1
204-207
In fact, it is the other way round: Coulomb’s law can now be employed to furnish a definition for a unit of charge In the relation, Eq (1 1), k is so far arbitrary
1
205-208
In the relation, Eq (1 1), k is so far arbitrary We can choose any positive value of k
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206-209
(1 1), k is so far arbitrary We can choose any positive value of k The choice of k determines the size of the unit of charge
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207-210
1), k is so far arbitrary We can choose any positive value of k The choice of k determines the size of the unit of charge In SI units, the value of k is about 9 × 109 2 2 Nm C
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208-211
We can choose any positive value of k The choice of k determines the size of the unit of charge In SI units, the value of k is about 9 × 109 2 2 Nm C The unit of charge that results from this choice is called a coulomb which we defined earlier in Section 1
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209-212
The choice of k determines the size of the unit of charge In SI units, the value of k is about 9 × 109 2 2 Nm C The unit of charge that results from this choice is called a coulomb which we defined earlier in Section 1 4
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210-213
In SI units, the value of k is about 9 × 109 2 2 Nm C The unit of charge that results from this choice is called a coulomb which we defined earlier in Section 1 4 Putting this value of k in Eq
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211-214
The unit of charge that results from this choice is called a coulomb which we defined earlier in Section 1 4 Putting this value of k in Eq (1
1
212-215
4 Putting this value of k in Eq (1 1), we see that for q1 = q2 = 1 C, r = 1 m F = 9 × 109 N That is, 1 C is the charge that when placed at a distance of 1 m from another charge of the same magnitude in vacuum experiences an electrical force of repulsion of magnitude * A torsion balance is a sensitive device to measure force
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213-216
Putting this value of k in Eq (1 1), we see that for q1 = q2 = 1 C, r = 1 m F = 9 × 109 N That is, 1 C is the charge that when placed at a distance of 1 m from another charge of the same magnitude in vacuum experiences an electrical force of repulsion of magnitude * A torsion balance is a sensitive device to measure force It was also used later by Cavendish to measure the very feeble gravitational force between two objects, to verify Newton’s Law of Gravitation
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214-217
(1 1), we see that for q1 = q2 = 1 C, r = 1 m F = 9 × 109 N That is, 1 C is the charge that when placed at a distance of 1 m from another charge of the same magnitude in vacuum experiences an electrical force of repulsion of magnitude * A torsion balance is a sensitive device to measure force It was also used later by Cavendish to measure the very feeble gravitational force between two objects, to verify Newton’s Law of Gravitation * Implicit in this is the assumption of additivity of charges and conservation: two charges (q/2 each) add up to make a total charge q
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215-218
1), we see that for q1 = q2 = 1 C, r = 1 m F = 9 × 109 N That is, 1 C is the charge that when placed at a distance of 1 m from another charge of the same magnitude in vacuum experiences an electrical force of repulsion of magnitude * A torsion balance is a sensitive device to measure force It was also used later by Cavendish to measure the very feeble gravitational force between two objects, to verify Newton’s Law of Gravitation * Implicit in this is the assumption of additivity of charges and conservation: two charges (q/2 each) add up to make a total charge q Charles Augustin de Coulomb (1736 – 1806) Coulomb, a French physicist, began his career as a military engineer in the West Indies
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216-219
It was also used later by Cavendish to measure the very feeble gravitational force between two objects, to verify Newton’s Law of Gravitation * Implicit in this is the assumption of additivity of charges and conservation: two charges (q/2 each) add up to make a total charge q Charles Augustin de Coulomb (1736 – 1806) Coulomb, a French physicist, began his career as a military engineer in the West Indies In 1776, he returned to Paris and retired to a small estate to do his scientific research
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217-220
* Implicit in this is the assumption of additivity of charges and conservation: two charges (q/2 each) add up to make a total charge q Charles Augustin de Coulomb (1736 – 1806) Coulomb, a French physicist, began his career as a military engineer in the West Indies In 1776, he returned to Paris and retired to a small estate to do his scientific research He invented a torsion balance to measure the quantity of a force and used it for determination of forces of electric attraction or repulsion between small charged spheres
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218-221
Charles Augustin de Coulomb (1736 – 1806) Coulomb, a French physicist, began his career as a military engineer in the West Indies In 1776, he returned to Paris and retired to a small estate to do his scientific research He invented a torsion balance to measure the quantity of a force and used it for determination of forces of electric attraction or repulsion between small charged spheres He thus arrived in 1785 at the inverse square law relation, now known as Coulomb’s law
1
219-222
In 1776, he returned to Paris and retired to a small estate to do his scientific research He invented a torsion balance to measure the quantity of a force and used it for determination of forces of electric attraction or repulsion between small charged spheres He thus arrived in 1785 at the inverse square law relation, now known as Coulomb’s law The law had been anticipated by Priestley and also by Cavendish earlier, though Cavendish never published his results
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220-223
He invented a torsion balance to measure the quantity of a force and used it for determination of forces of electric attraction or repulsion between small charged spheres He thus arrived in 1785 at the inverse square law relation, now known as Coulomb’s law The law had been anticipated by Priestley and also by Cavendish earlier, though Cavendish never published his results Coulomb also found the inverse square law of force between unlike and like magnetic poles
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221-224
He thus arrived in 1785 at the inverse square law relation, now known as Coulomb’s law The law had been anticipated by Priestley and also by Cavendish earlier, though Cavendish never published his results Coulomb also found the inverse square law of force between unlike and like magnetic poles CHARLES AUGUSTIN DE COULOMB (1736 –1806) Rationalised 2023-24 8 Physics 9 × 109 N
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222-225
The law had been anticipated by Priestley and also by Cavendish earlier, though Cavendish never published his results Coulomb also found the inverse square law of force between unlike and like magnetic poles CHARLES AUGUSTIN DE COULOMB (1736 –1806) Rationalised 2023-24 8 Physics 9 × 109 N One coulomb is evidently too big a unit to be used
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Coulomb also found the inverse square law of force between unlike and like magnetic poles CHARLES AUGUSTIN DE COULOMB (1736 –1806) Rationalised 2023-24 8 Physics 9 × 109 N One coulomb is evidently too big a unit to be used In practice, in electrostatics, one uses smaller units like 1 mC or 1 mC
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CHARLES AUGUSTIN DE COULOMB (1736 –1806) Rationalised 2023-24 8 Physics 9 × 109 N One coulomb is evidently too big a unit to be used In practice, in electrostatics, one uses smaller units like 1 mC or 1 mC The constant k in Eq
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225-228
One coulomb is evidently too big a unit to be used In practice, in electrostatics, one uses smaller units like 1 mC or 1 mC The constant k in Eq (1
1
226-229
In practice, in electrostatics, one uses smaller units like 1 mC or 1 mC The constant k in Eq (1 1) is usually put as k = 1/4pe0 for later convenience, so that Coulomb’s law is written as 0 1 2 2 1 4 q q F r ε = π (1
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227-230
The constant k in Eq (1 1) is usually put as k = 1/4pe0 for later convenience, so that Coulomb’s law is written as 0 1 2 2 1 4 q q F r ε = π (1 2) e0 is called the permittivity of free space
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228-231
(1 1) is usually put as k = 1/4pe0 for later convenience, so that Coulomb’s law is written as 0 1 2 2 1 4 q q F r ε = π (1 2) e0 is called the permittivity of free space The value of e0 in SI units is 0  = 8
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229-232
1) is usually put as k = 1/4pe0 for later convenience, so that Coulomb’s law is written as 0 1 2 2 1 4 q q F r ε = π (1 2) e0 is called the permittivity of free space The value of e0 in SI units is 0  = 8 854 × 10–12 C2 N–1m–2 Since force is a vector, it is better to write Coulomb’s law in the vector notation
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230-233
2) e0 is called the permittivity of free space The value of e0 in SI units is 0  = 8 854 × 10–12 C2 N–1m–2 Since force is a vector, it is better to write Coulomb’s law in the vector notation Let the position vectors of charges q1 and q2 be r1 and r2 respectively [see Fig
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231-234
The value of e0 in SI units is 0  = 8 854 × 10–12 C2 N–1m–2 Since force is a vector, it is better to write Coulomb’s law in the vector notation Let the position vectors of charges q1 and q2 be r1 and r2 respectively [see Fig 1
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854 × 10–12 C2 N–1m–2 Since force is a vector, it is better to write Coulomb’s law in the vector notation Let the position vectors of charges q1 and q2 be r1 and r2 respectively [see Fig 1 3(a)]
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233-236
Let the position vectors of charges q1 and q2 be r1 and r2 respectively [see Fig 1 3(a)] We denote force on q1 due to q2 by F12 and force on q2 due to q1 by F21
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1 3(a)] We denote force on q1 due to q2 by F12 and force on q2 due to q1 by F21 The two point charges q1 and q2 have been numbered 1 and 2 for convenience and the vector leading from 1 to 2 is denoted by r21: r21 = r2 – r1 In the same way, the vector leading from 2 to 1 is denoted by r12: r12 = r1 – r2 = – r21 The magnitude of the vectors r21 and r12 is denoted by r21 and r12, respectively (r12 = r21)
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235-238
3(a)] We denote force on q1 due to q2 by F12 and force on q2 due to q1 by F21 The two point charges q1 and q2 have been numbered 1 and 2 for convenience and the vector leading from 1 to 2 is denoted by r21: r21 = r2 – r1 In the same way, the vector leading from 2 to 1 is denoted by r12: r12 = r1 – r2 = – r21 The magnitude of the vectors r21 and r12 is denoted by r21 and r12, respectively (r12 = r21) The direction of a vector is specified by a unit vector along the vector
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236-239
We denote force on q1 due to q2 by F12 and force on q2 due to q1 by F21 The two point charges q1 and q2 have been numbered 1 and 2 for convenience and the vector leading from 1 to 2 is denoted by r21: r21 = r2 – r1 In the same way, the vector leading from 2 to 1 is denoted by r12: r12 = r1 – r2 = – r21 The magnitude of the vectors r21 and r12 is denoted by r21 and r12, respectively (r12 = r21) The direction of a vector is specified by a unit vector along the vector To denote the direction from 1 to 2 (or from 2 to 1), we define the unit vectors: ɵ 21 21 21 = r r r , ɵ ɵ ɵ 12 12 21 12 12 , = − r r r r r Coulomb’s force law between two point charges q1 and q2 located at r1 and r2, respectively is then expressed as ɵ 1 2 21 21 2 21 41 ε = π F r o q rq (1
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237-240
The two point charges q1 and q2 have been numbered 1 and 2 for convenience and the vector leading from 1 to 2 is denoted by r21: r21 = r2 – r1 In the same way, the vector leading from 2 to 1 is denoted by r12: r12 = r1 – r2 = – r21 The magnitude of the vectors r21 and r12 is denoted by r21 and r12, respectively (r12 = r21) The direction of a vector is specified by a unit vector along the vector To denote the direction from 1 to 2 (or from 2 to 1), we define the unit vectors: ɵ 21 21 21 = r r r , ɵ ɵ ɵ 12 12 21 12 12 , = − r r r r r Coulomb’s force law between two point charges q1 and q2 located at r1 and r2, respectively is then expressed as ɵ 1 2 21 21 2 21 41 ε = π F r o q rq (1 3) Some remarks on Eq
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238-241
The direction of a vector is specified by a unit vector along the vector To denote the direction from 1 to 2 (or from 2 to 1), we define the unit vectors: ɵ 21 21 21 = r r r , ɵ ɵ ɵ 12 12 21 12 12 , = − r r r r r Coulomb’s force law between two point charges q1 and q2 located at r1 and r2, respectively is then expressed as ɵ 1 2 21 21 2 21 41 ε = π F r o q rq (1 3) Some remarks on Eq (1
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239-242
To denote the direction from 1 to 2 (or from 2 to 1), we define the unit vectors: ɵ 21 21 21 = r r r , ɵ ɵ ɵ 12 12 21 12 12 , = − r r r r r Coulomb’s force law between two point charges q1 and q2 located at r1 and r2, respectively is then expressed as ɵ 1 2 21 21 2 21 41 ε = π F r o q rq (1 3) Some remarks on Eq (1 3) are relevant: · Equation (1
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240-243
3) Some remarks on Eq (1 3) are relevant: · Equation (1 3) is valid for any sign of q1 and q2 whether positive or negative
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(1 3) are relevant: · Equation (1 3) is valid for any sign of q1 and q2 whether positive or negative If q1 and q2 are of the same sign (either both positive or both negative), F21 is along ˆr 21, which denotes repulsion, as it should be for like charges
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242-245
3) are relevant: · Equation (1 3) is valid for any sign of q1 and q2 whether positive or negative If q1 and q2 are of the same sign (either both positive or both negative), F21 is along ˆr 21, which denotes repulsion, as it should be for like charges If q1 and q2 are of opposite signs, F21 is along – ɵr 21(= ɵr 12), which denotes attraction, as expected for unlike charges
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3) is valid for any sign of q1 and q2 whether positive or negative If q1 and q2 are of the same sign (either both positive or both negative), F21 is along ˆr 21, which denotes repulsion, as it should be for like charges If q1 and q2 are of opposite signs, F21 is along – ɵr 21(= ɵr 12), which denotes attraction, as expected for unlike charges Thus, we do not have to write separate equations for the cases of like and unlike charges
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If q1 and q2 are of the same sign (either both positive or both negative), F21 is along ˆr 21, which denotes repulsion, as it should be for like charges If q1 and q2 are of opposite signs, F21 is along – ɵr 21(= ɵr 12), which denotes attraction, as expected for unlike charges Thus, we do not have to write separate equations for the cases of like and unlike charges Equation (1
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If q1 and q2 are of opposite signs, F21 is along – ɵr 21(= ɵr 12), which denotes attraction, as expected for unlike charges Thus, we do not have to write separate equations for the cases of like and unlike charges Equation (1 3) takes care of both cases correctly [Fig
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Thus, we do not have to write separate equations for the cases of like and unlike charges Equation (1 3) takes care of both cases correctly [Fig 1
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Equation (1 3) takes care of both cases correctly [Fig 1 3(b)]
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3) takes care of both cases correctly [Fig 1 3(b)] FIGURE 1
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1 3(b)] FIGURE 1 3 (a) Geometry and (b) Forces between charges
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3(b)] FIGURE 1 3 (a) Geometry and (b) Forces between charges Rationalised 2023-24 Electric Charges and Fields 9 EXAMPLE 1
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251-254
FIGURE 1 3 (a) Geometry and (b) Forces between charges Rationalised 2023-24 Electric Charges and Fields 9 EXAMPLE 1 3 Interactive animation on Coulomb’s law: http://webphysics
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3 (a) Geometry and (b) Forces between charges Rationalised 2023-24 Electric Charges and Fields 9 EXAMPLE 1 3 Interactive animation on Coulomb’s law: http://webphysics davidson
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253-256
Rationalised 2023-24 Electric Charges and Fields 9 EXAMPLE 1 3 Interactive animation on Coulomb’s law: http://webphysics davidson edu/physlet_resources/bu_semester2/menu_semester2
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3 Interactive animation on Coulomb’s law: http://webphysics davidson edu/physlet_resources/bu_semester2/menu_semester2 html · The force F12 on charge q1 due to charge q2, is obtained from Eq
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davidson edu/physlet_resources/bu_semester2/menu_semester2 html · The force F12 on charge q1 due to charge q2, is obtained from Eq (1
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256-259
edu/physlet_resources/bu_semester2/menu_semester2 html · The force F12 on charge q1 due to charge q2, is obtained from Eq (1 3), by simply interchanging 1 and 2, i
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html · The force F12 on charge q1 due to charge q2, is obtained from Eq (1 3), by simply interchanging 1 and 2, i e
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258-261
(1 3), by simply interchanging 1 and 2, i e , 1 2 12 12 21 2 0 12 1 ˆ 4 ε = = − π F r F q q r Thus, Coulomb’s law agrees with the Newton’s third law
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259-262
3), by simply interchanging 1 and 2, i e , 1 2 12 12 21 2 0 12 1 ˆ 4 ε = = − π F r F q q r Thus, Coulomb’s law agrees with the Newton’s third law · Coulomb’s law [Eq
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260-263
e , 1 2 12 12 21 2 0 12 1 ˆ 4 ε = = − π F r F q q r Thus, Coulomb’s law agrees with the Newton’s third law · Coulomb’s law [Eq (1
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, 1 2 12 12 21 2 0 12 1 ˆ 4 ε = = − π F r F q q r Thus, Coulomb’s law agrees with the Newton’s third law · Coulomb’s law [Eq (1 3)] gives the force between two charges q1 and q2 in vacuum
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· Coulomb’s law [Eq (1 3)] gives the force between two charges q1 and q2 in vacuum If the charges are placed in matter or the intervening space has matter, the situation gets complicated due to the presence of charged constituents of matter
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(1 3)] gives the force between two charges q1 and q2 in vacuum If the charges are placed in matter or the intervening space has matter, the situation gets complicated due to the presence of charged constituents of matter We shall consider electrostatics in matter in the next chapter
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3)] gives the force between two charges q1 and q2 in vacuum If the charges are placed in matter or the intervening space has matter, the situation gets complicated due to the presence of charged constituents of matter We shall consider electrostatics in matter in the next chapter Example 1
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If the charges are placed in matter or the intervening space has matter, the situation gets complicated due to the presence of charged constituents of matter We shall consider electrostatics in matter in the next chapter Example 1 3 Coulomb’s law for electrostatic force between two point charges and Newton’s law for gravitational force between two stationary point masses, both have inverse-square dependence on the distance between the charges and masses respectively
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We shall consider electrostatics in matter in the next chapter Example 1 3 Coulomb’s law for electrostatic force between two point charges and Newton’s law for gravitational force between two stationary point masses, both have inverse-square dependence on the distance between the charges and masses respectively (a) Compare the strength of these forces by determining the ratio of their magnitudes (i) for an electron and a proton and (ii) for two protons
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Example 1 3 Coulomb’s law for electrostatic force between two point charges and Newton’s law for gravitational force between two stationary point masses, both have inverse-square dependence on the distance between the charges and masses respectively (a) Compare the strength of these forces by determining the ratio of their magnitudes (i) for an electron and a proton and (ii) for two protons (b) Estimate the accelerations of electron and proton due to the electrical force of their mutual attraction when they are 1 Å (= 10-10 m) apart
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3 Coulomb’s law for electrostatic force between two point charges and Newton’s law for gravitational force between two stationary point masses, both have inverse-square dependence on the distance between the charges and masses respectively (a) Compare the strength of these forces by determining the ratio of their magnitudes (i) for an electron and a proton and (ii) for two protons (b) Estimate the accelerations of electron and proton due to the electrical force of their mutual attraction when they are 1 Å (= 10-10 m) apart (mp = 1
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(a) Compare the strength of these forces by determining the ratio of their magnitudes (i) for an electron and a proton and (ii) for two protons (b) Estimate the accelerations of electron and proton due to the electrical force of their mutual attraction when they are 1 Å (= 10-10 m) apart (mp = 1 67 × 10–27 kg, me = 9
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(b) Estimate the accelerations of electron and proton due to the electrical force of their mutual attraction when they are 1 Å (= 10-10 m) apart (mp = 1 67 × 10–27 kg, me = 9 11 × 10–31 kg) Solution (a) (i) The electric force between an electron and a proton at a distance r apart is: 2 2 0 41 e e F r ε = − π where the negative sign indicates that the force is attractive
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(mp = 1 67 × 10–27 kg, me = 9 11 × 10–31 kg) Solution (a) (i) The electric force between an electron and a proton at a distance r apart is: 2 2 0 41 e e F r ε = − π where the negative sign indicates that the force is attractive The corresponding gravitational force (always attractive) is: 2 p e G m m F G r = − where mp and me are the masses of a proton and an electron respectively
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67 × 10–27 kg, me = 9 11 × 10–31 kg) Solution (a) (i) The electric force between an electron and a proton at a distance r apart is: 2 2 0 41 e e F r ε = − π where the negative sign indicates that the force is attractive The corresponding gravitational force (always attractive) is: 2 p e G m m F G r = − where mp and me are the masses of a proton and an electron respectively 2 39 0 2
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11 × 10–31 kg) Solution (a) (i) The electric force between an electron and a proton at a distance r apart is: 2 2 0 41 e e F r ε = − π where the negative sign indicates that the force is attractive The corresponding gravitational force (always attractive) is: 2 p e G m m F G r = − where mp and me are the masses of a proton and an electron respectively 2 39 0 2 4 10 4 e G p e F e F εGm m = = × π (ii) On similar lines, the ratio of the magnitudes of electric force to the gravitational force between two protons at a distance r apart is: FF e Gm m e G p p = = 2 4πε0 1
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The corresponding gravitational force (always attractive) is: 2 p e G m m F G r = − where mp and me are the masses of a proton and an electron respectively 2 39 0 2 4 10 4 e G p e F e F εGm m = = × π (ii) On similar lines, the ratio of the magnitudes of electric force to the gravitational force between two protons at a distance r apart is: FF e Gm m e G p p = = 2 4πε0 1 3 × 1036 However, it may be mentioned here that the signs of the two forces are different
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2 39 0 2 4 10 4 e G p e F e F εGm m = = × π (ii) On similar lines, the ratio of the magnitudes of electric force to the gravitational force between two protons at a distance r apart is: FF e Gm m e G p p = = 2 4πε0 1 3 × 1036 However, it may be mentioned here that the signs of the two forces are different For two protons, the gravitational force is attractive in nature and the Coulomb force is repulsive
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276-279
4 10 4 e G p e F e F εGm m = = × π (ii) On similar lines, the ratio of the magnitudes of electric force to the gravitational force between two protons at a distance r apart is: FF e Gm m e G p p = = 2 4πε0 1 3 × 1036 However, it may be mentioned here that the signs of the two forces are different For two protons, the gravitational force is attractive in nature and the Coulomb force is repulsive The actual values of these forces between two protons inside a nucleus (distance between two protons is ~ 10-15 m inside a nucleus) are Fe ~ 230 N, whereas, FG ~ 1
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3 × 1036 However, it may be mentioned here that the signs of the two forces are different For two protons, the gravitational force is attractive in nature and the Coulomb force is repulsive The actual values of these forces between two protons inside a nucleus (distance between two protons is ~ 10-15 m inside a nucleus) are Fe ~ 230 N, whereas, FG ~ 1 9 × 10–34 N
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For two protons, the gravitational force is attractive in nature and the Coulomb force is repulsive The actual values of these forces between two protons inside a nucleus (distance between two protons is ~ 10-15 m inside a nucleus) are Fe ~ 230 N, whereas, FG ~ 1 9 × 10–34 N The (dimensionless) ratio of the two forces shows that electrical forces are enormously stronger than the gravitational forces
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The actual values of these forces between two protons inside a nucleus (distance between two protons is ~ 10-15 m inside a nucleus) are Fe ~ 230 N, whereas, FG ~ 1 9 × 10–34 N The (dimensionless) ratio of the two forces shows that electrical forces are enormously stronger than the gravitational forces Rationalised 2023-24 10 Physics (b) The electric force F exerted by a proton on an electron is same in magnitude to the force exerted by an electron on a proton; however, the masses of an electron and a proton are different
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9 × 10–34 N The (dimensionless) ratio of the two forces shows that electrical forces are enormously stronger than the gravitational forces Rationalised 2023-24 10 Physics (b) The electric force F exerted by a proton on an electron is same in magnitude to the force exerted by an electron on a proton; however, the masses of an electron and a proton are different Thus, the magnitude of force is |F| = 41 0 2 2 πε re = 8
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The (dimensionless) ratio of the two forces shows that electrical forces are enormously stronger than the gravitational forces Rationalised 2023-24 10 Physics (b) The electric force F exerted by a proton on an electron is same in magnitude to the force exerted by an electron on a proton; however, the masses of an electron and a proton are different Thus, the magnitude of force is |F| = 41 0 2 2 πε re = 8 987 × 109 Nm2/C2 × (1
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282-285
Rationalised 2023-24 10 Physics (b) The electric force F exerted by a proton on an electron is same in magnitude to the force exerted by an electron on a proton; however, the masses of an electron and a proton are different Thus, the magnitude of force is |F| = 41 0 2 2 πε re = 8 987 × 109 Nm2/C2 × (1 6 ×10–19C)2 / (10–10m)2 = 2
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283-286
Thus, the magnitude of force is |F| = 41 0 2 2 πε re = 8 987 × 109 Nm2/C2 × (1 6 ×10–19C)2 / (10–10m)2 = 2 3 × 10–8 N Using Newton’s second law of motion, F = ma, the acceleration that an electron will undergo is a = 2
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284-287
987 × 109 Nm2/C2 × (1 6 ×10–19C)2 / (10–10m)2 = 2 3 × 10–8 N Using Newton’s second law of motion, F = ma, the acceleration that an electron will undergo is a = 2 3×10–8 N / 9
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285-288
6 ×10–19C)2 / (10–10m)2 = 2 3 × 10–8 N Using Newton’s second law of motion, F = ma, the acceleration that an electron will undergo is a = 2 3×10–8 N / 9 11 ×10–31 kg = 2
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286-289
3 × 10–8 N Using Newton’s second law of motion, F = ma, the acceleration that an electron will undergo is a = 2 3×10–8 N / 9 11 ×10–31 kg = 2 5 × 1022 m/s2 Comparing this with the value of acceleration due to gravity, we can conclude that the effect of gravitational field is negligible on the motion of electron and it undergoes very large accelerations under the action of Coulomb force due to a proton
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287-290
3×10–8 N / 9 11 ×10–31 kg = 2 5 × 1022 m/s2 Comparing this with the value of acceleration due to gravity, we can conclude that the effect of gravitational field is negligible on the motion of electron and it undergoes very large accelerations under the action of Coulomb force due to a proton The value for acceleration of the proton is 2
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288-291
11 ×10–31 kg = 2 5 × 1022 m/s2 Comparing this with the value of acceleration due to gravity, we can conclude that the effect of gravitational field is negligible on the motion of electron and it undergoes very large accelerations under the action of Coulomb force due to a proton The value for acceleration of the proton is 2 3 × 10–8 N / 1
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289-292
5 × 1022 m/s2 Comparing this with the value of acceleration due to gravity, we can conclude that the effect of gravitational field is negligible on the motion of electron and it undergoes very large accelerations under the action of Coulomb force due to a proton The value for acceleration of the proton is 2 3 × 10–8 N / 1 67 × 10–27 kg = 1