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Unformatted text preview: ove left. The field is weaker to the left so the acceleration will decrease. As long
as there is a force on the electron, its speed will continue to increase to the left. (ii) 1 point
1 point
1 point
1 point 3 points For using conservation of energy with U = qV
12
mu = q DV
2
u = 2 q DV m
For correct substitution of values into either equation above ( u = 2 1.6 ¥ 10 19 ) ( C (10 V ) 9.11 ¥ 10 31 kg ) For the correct answer 1 point 1 point
1 point u = 1.9 ¥ 10 m s
Note: Substitution point was awarded if correct answer was indicated.
6 Copyright © 2005 by College Entrance Examination Board. All rights reserved.
Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for AP students and parents). 3 AP® PHYSICS C ELECTRICITY & MAGNETISM
2005 SCORING GUIDELINES
Question 1 (continued)
Distribution
of points
(c) 2 points DV
r
20 V
E=
0.01 m
For the correct answer with correct units
E = 2000 V m or 2000 N C
For the correct assumption that the field is close enough to uniform in this region to
do a calculation as if it were
E= (d) 1 point 1 point 2 points For drawing a curved line concave up or concave right that passes through point D and
at least three electric field lines
For drawing the curved line perpendicular to at least three field lines 1 point
1 point Copyright © 2005 by College Entrance Examination Board. All...
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This note was uploaded on 08/05/2009 for the course PHYS 101 taught by Professor Reich during the Spring '08 term at Johns Hopkins.
 Spring '08
 Reich
 Physics, Magnetism

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