الفيزياء العامة الجزء الثاني#موقع الفيزياء.كوم

Lectures in General Physics
3.8 Solution of some selected problems
Example 3.3
A positive point charge q of mass m is
released from rest in a uniform electric
field E r directed along the x-axis as shown
in figure 3.8, describe its motion.
V=0
E
V
Solution
The acceleration is given by
X
Figure 3.8
a = qE/m
Since the motion of the particle in one dimension, then we can apply the
equations of kinematics in one dimension
x-x o = v 0 t+ ½ at 2 v = v 0 + at v 2 =v o 2 + 2a(x-x o )
Taking x o = 0 and v 0 = 0
x = ½ at 2 = (qE/2m) t 2
v = at = (qE/m) t
v 2 =2ax = (2qE/m)x (3.7)
Dr. Hazem Falah Sakeek