PHYS 135B Homework Set 4
Giancoli 6th Edition
Chap 16:
1-) P 66 . Two point charges,
C7.6
1
µ
−=Q
and
CQ
µ
8.1
2
=
ar e loc ate d bet wee n two
oppositely charged parallel plates, as shown in Fig. 16–65. The two charges are
separated by a distance of
m. 34.0=x
Assume that the electric field produced by the
charged plates is uniform and equal to
.CN000,73=E
. Calculate the net electrostatic
fo rc e o n
1
Q
and give its direction.
2-)P3 7 ( a) Determine the electric field
E
at the origin 0 in Fig. 16–56 due to the tw o
charges at A and B. (b) Repeat, but let the charge at B be reversed in sign.
3-) P40. Determine the direction and magnitude of the electric field at the point P
shown in Fig. 16–59. The two charges are separated by a distance of 2a. Point P is on the
perpendicular bisector of the line joining the charges, a distance x from the midp oint
between them. Express your answers in terms of Q, x, a, an d k.
4-) P57. A water droplet of radius 0.018 mm remains stationary in the air. If the
downwa rd-directed electric field of the Earth is
,CN150
how many excess electron
charges must the water droplet have?
5-) P6 7. A point charge
)g0.1( =m
at the end of an insulating string of length 55 cm is
observed to be in equilibrium in a uniform horizontal electric field of
,CN000,12
when
the pendulum’s position is as shown in Fig. 16–66, with the charge 12 cm above the
lowest (vertical) position. If the field points to the right in Fig. 16–66, determine the
magnitude and sign of the point charge.