Download presentation

Presentation is loading. Please wait.

Published bySerena Jersey Modified over 2 years ago

1
Today 3/12 Plates if charge E-Field Potential HW:“Plate Potential” Due Friday, 3/14

2
(+) How big is E? (-) E net = 0

3
0 = Q/A Charged conducting plate What’s wrong with this picture? A = Area of one side

4
L = 0 /2 Charged conducting plate Free charge always goes to surface of conductor. R = 0 /2

5
L = 0 /2 Charged conducting plate R = 0 /2 What is the electric field inside the conductor? E L = L /2 0 = 0 /4 0

6
L = 0 /2 Charged conducting plate R = 0 /2 What is the electric field inside the conductor? E R = R /2 0 = 0 /4 0

7
L = 0 /2 Charged conducting plate R = 0 /2 What is the electric field inside the conductor? The electric field is zero everywhere inside the conductor. Always, any conductor, no exceptions.

8
q=+1C What happens if I let it go?

9
KE = 0KE = 100 J A B Assume the particle gains 100 joules of kinetic energy as it moves from A to B. q=+1C

10
A B Now I stop it at B. How much work must I do to move it back to A? +100 J How does the potential energy change in moving from B to A? +100 J PE BA = +100 J PE AB = -100 J q=+1C

11
A B PE BA = +200 J PE AB = -200 J What if q=+2C? How much work must I do to move it back to A? How does the potential energy change in moving from B to A? +200 J q=+2C

12
A B Now we are back to our original definition. PE BA = (+100 J/C)x(q) V BA tells us how much PE changes when +1C is moved from B to A. PE BA = V BA q V BA = +100 J/C q=+1C

13
A B What if q = -1C? First I must turn my hand around. q= -1C

14
A B What if q= -1C? How much work must I do to move it back to A? -100 J How does the potential energy change in moving from B to A? -100 J PE BA = (+100 J/C)x(q) PE BA = (+100 J/C)x(-1) V BA tells us how much PE changes when +1C is moved from B to A. PE BA = V BA q q= -1C

15
A B What if q= -1C? How much work must I do to move it back to A? -100 J How does the potential energy change in moving from B to A? -100 J PE BA = (+100 J/C)x(q) PE BA = (+100 J/C)x(-1) V BA does not depend on the sign of the point charge but PE BA does!!!!! PE BA = V BA q q= -1C

16
A B V AB = -100 J/C V AB = -100 volts A proton is released from rest at A. What is its speed when it reaches B? m= 1.7 x 10 -27 kg q= 1.6 x 10 -19 C PE AB = q V AB PE AB = q -100 J/C) PE AB = -1.6 x 10 -17 J What happens to the kinetic energy?

17
A B KE AB = +1.6 x 10 -17 J A proton is released from rest at A. What is its speed when it reaches B? m= 1.7 x 10 -27 kg q= 1.6 x 10 -19 C mv 2 = +1.6 x 10 -17 J v = 1.4 x 10 5 m/s What happens to the kinetic energy? PE AB = -1.6 x 10 -17 J

18
A B A B What direction is the force on an electron? EF

19
A B V AB = -100 J/C V BA = +100 J/C An electron is released from rest at B. What is its speed when it reaches A? m= 9.1 x 10 -31 kg q= -1.6 x 10 -19 C PE BA = q V BA PE BA = q +100 J/C) PE BA = -1.6 x 10 -17 J What happens to the kinetic energy?

20
A B KE BA = +1.6 x 10 -17 J mv 2 = +1.6 x 10 -17 J v = 5.9 x 10 6 m/s An electron is released from rest at B. What is its speed when it reaches A? m= 9.1 x 10 -31 kg q= -1.6 x 10 -19 C What happens to the kinetic energy? PE BA = -1.6 x 10 -17 J

21
B A V AB = ?

22
B A How does doubling the E-field affect V AB ? V AB = ? V AB doubles

23
B new A How does moving point B affect V AB ? V AB = ? How does V AB depend on E and D? D Anything else? V AB is halved B old

24
B A KE AB = 0 constant speed v0v0 v0v0 KE A =1/2 mv 0 2 KE B =1/2 mv 0 2 How much work must I do to move the charge from A to B? D

25
B A F E = qEF Hq W AB = F E x D W AB = qED W AB = F Hq x D

26
B A What is the change in potential energy in going from A to B? F E = qE F Hq W AB = qED PE AB = qED PE AB = q V AB V AB = ED AB W AB = qED Only applies when the field is uniform over the distance. V AB ‘s sign depends on the direction of E. In this case it’s positive.

Similar presentations

OK

1 My Chapter 17 Lecture Outline. 2 Chapter 17: Electric Potential Electric Potential Energy Electric Potential How are the E-field and Electric Potential.

1 My Chapter 17 Lecture Outline. 2 Chapter 17: Electric Potential Electric Potential Energy Electric Potential How are the E-field and Electric Potential.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on natural and artificial satellites of planets Ppt on wildlife and vegetation conservation Ppt on global warming free download Ppt on revolt of 1857 map Ppt on credit policy document Ppt on fast food in hindi Ppt on total internal reflection images Ppt on reverse mortgage Ppt on upcoming technologies in computer science Ppt on principles of management for class 12