(a) q 1
q 2
q 3
(b) q 1
q 2
q 3
(c) |q 1 | > |q 2 | > |q 3 |
|q 1 | > |q 3 | > |q 2 |
|q 2 | > |q 1 | > |q 3 |
|q 2 | > |q 3 | > |q 1 |
|q 3 | > |q 1 | > |q 2 |
|q 3 | > |q 2 | > |q 1 |
(d) times stronger
7.4 The three electric field diagrams labeled "1",
"2", and "3" in the accompanying illustration
each represent the field around two charged
particles of equal magnitude. (a) Which
diagram has a positive charge and a negative
charge? (b) Which diagram has two positive
charges? (c) Which diagram has two negative
charges?
(a) 1 2 3
(b) 1 2 3
(c) 1 2 3
7.5 Two point charges, +4q and íq, are located near each other. Sketch a diagram of the electric field generated by these two
charges, including some indication of how the field lines behave between the particles as well as at greater distances from
them.Section 8 - Describing the force exerted by an external electric field
8.1 A particle of mass 1.20 kg with a charge of +2.30 mC is shot into a region with an electric field of strength 18.0 N/C, having a
direction opposite the particle's velocity. If the particle has an initial speed of 3.10 m/s, how long does it take to come to a
complete (though momentary) standstill? Assume there are no other forces acting on the particle.
s
8.2 Protons carry an electric charge of e = 1.60×10í^19 C, electrons carry a charge of íe, and neutrons are electrically neutral.
Protons and neutrons have a mass of 1.67×10í^27 kg, and electrons have a mass of 9.11×10í^31 kg. A uniform electric field can
exert a force on a charged particle that effectively neutralizes the force of gravity on the particle, causing it to be "weightless."
What is the strength of the electric field that will levitate (a) a proton? (b) an electron? (c) an alpha particle (two protons and
two neutrons)?
(a) N/C
(b) N/C
(c) N/C
8.3 An electron (charge í1.60×10í^19 C, mass 9.11×10í^31 kg) is in a uniform electric field of strength 543 N/C in the positive
direction. (a) What is the force on the electron? (b) What is the acceleration of the electron? (c) What is the electron's speed
after 1.05×10í^8 s? (d) What fraction of the speed of light (3.00×10^8 m/s) is your answer to part c? Be careful of the sign in
each of your answers.
(a) N
(b) m/s^2
(c) m/s
(d)
8.4 A proton (charge 1.60×10í^19 C, mass 1.67×10í^27 kg) is in a uniform electric field of strength 2.51×10^4 N/C. (a) What is the
magnitude of the force on the proton? (b) What is the magnitude of acceleration of the proton? (c) What is the proton's speed
after 1.25 ns?
(a) N
(b) m/s^2
(c) m/s(^434) Copyright 2007 Kinetic Books Co. Chapter 23 Problems