الفيزياء العامة الجزء الثاني#موقع الفيزياء.كوم

Lectures in General Physics
3.10 Problems
3.1) The electric force on a point
charge of 4.0µC at some point is
6.9×10 -4 N in the positive x
direction. What is the value of the
electric field at that point?
3.2) What are the magnitude and
direction of the electric field that
will balance the weight of (a) an
electron and (b) a proton?
(Use the data in Table l.)
3.3) A point charge of -5.2µC is
located at the origin. Find the
electric field (a) on the x-axis at
x=3 m, (b) on the y-axis at y= -4m,
(c) at the point with coordinates
x=2m, y=2m.
3.4) What is the magnitude of a
point charge chosen so that the
electric field 50cm away has the
magnitude 2.0N/C?
3.5) Two point charges of
magnitude +2.0×10 -7 C and
+8.5×10 -11 C are 12cm apart. (a)
What electric field does each
produce at the site of the other? (b)
What force acts on each?
3.6) An electron and a proton are
each placed at rest in an external
electric field of 520N/C. Calculate
the speed of each particle after
48nanoseconds.
3.7) The electrons in a particle beam
each have a kinetic energy of
1.6×10 -17 J. What are the magnitude
and direction of the electric field
that will stop these electrons in a
distance of 10cm?
3.8) A particle having a charge of -
2.0×10 -9 C is acted on by a
downward electric force of 3.0×10 -
6 N in a uniform electric field. (a)
What is the strength of the electric
field? (b) What is the magnitude
and direction of the electric force
exerted on a proton placed in this
field? (c) What is the gravitational
force on the proton? (d) What is the
ratio of the electric to the
gravitational forces in this case?
3.9) Find the total electric field
along the line of the two charges
shown in figure 3.16 at the point
midway between them.
− 4.7µC
- +
3m
Figure 3.16
+ 9µ C
3.10) What is the magnitude and
direction of an electric field that
will balance the weight of (a) an
electron and (b) a proton?
Dr. Hazem Falah Sakeek