Download Movement of Charged Particles

Movement of Charged Particles
Electrostatics
Lesson 8
Chapter 11
When an electron is placed near a negatively charged
plate it will have high potential energy.
This electric force gives the electron kinetic energy.
A change in energy can only occur when work is done
on an object.
W=∆E
Work done by the field = ∆ kinetic energy.
Fe•d = Ekf - Eki
Eqd = 0.5 m (vf2 - vi2)
Since E = V/d then V= Ed so
Vq = 0.5 m (vf2 - vi2)
An electron is placed in an electric field of 1.00 x 104 N/C to the
left. The plates are 10.0 mm apart.
Determine
the change in kinetic energy
the velocity with which the electron hits the positive plate
the change in potential energy
An alpha particle is placed in an electric field. The
vertical plates are connected to a 100 V source of
potential energy. Calculate
the work done by the field on the alpha particle
the gain of kinetic energy of the alpha particle.
ratio of the work done per charge
Electron Volt
unit of energy
Definition: One electron volt is the energy
gained by a particle having a charge of one
elementary charge and is accelerated through a
1.0 V potential difference.
1.00 eV = 1.60 x 10-19 J (see data sheet)
Suppose that one electron is accelerated through
a 9.00 V potential difference. How much energy
does the charge now have?
show answer in J and eV
NOTE: IF the question asks for velocity then you
MUST have energy in Joules.
A proton, traveling at 1.5 x 106 m/s, enters perpendicular to
an electric field between parallel plates that are 2.0 mm
apart and charged by a 9.0 V battery. If the proton enters at
the positive plate’s edge, how far into the field will it go
before it contacts the negative plate?
Assignment
Read p.570-575
Do p.571 #1,2
p. 573 #1,2
p. 574 #1,2
Review: SNAP p. 90 all