Download (2) electron

Triple Gun Assembly (R,B,G beams) of a color television tube
As this electron enters the E-field, it will
1) speed up.
2) slow down.
3) maintain constant speed.
As this electron enters the E-field,
Its path will be deflected (nudged)
1) up.
2) down.
3) neither,only accelerated forward.
Electron Gun
0.3 cm
-e
2 centimeters
vo = 8.4107 m/sec
me = 9.1110-31 kg
1e = 1.6010-19 C
Emax = ?
vo
0.3 cm
-e
2 centimeters
The time each individual electron spends between the two plates
1. x  v0t  t  2.0 cm / v0
2. x  v0t  t  0.3 cm / v0
3.
4.
5.
6.
1 2
x  at  t  2( 2.0 cm ) a
2
1 2
x  at  t  2(0.3 cm ) a
2
2
 v0  v0  2a ( 2.0 cm )
1 2
x  v0t  at  t 
2
a
2
 v0  v0  2a (0.3 cm )
1 2
x  v0t  at  t 
2
a
vo
0.3 cm
-e
2 centimeters
x = voxt +
2
½axt
0
y = voyt +
0
2
½ayt
Concept Review
A man lifts a 5 kg rock 1 meter off the
ground. The potential energy of the
rock is about
1) 5 J
2) 50 J
3) 100 J
4) 500 J
h=1m
Concept Review
A man lifts a 5 kg rock 1 meter off the
ground. The potential energy of the
rock is about
1) 5 J
2) 50 J
3) 100 J
4) 500 J
h=1m
About how much work did the man have to do?
1) 5 J
2) 50 J
3) 100 J
4) 500 J
5) cannot answer from the information given
Concept Review Test
The balls in the figure are identical. When released
from rest, which has a greater kinetic energy when it
gets to the bottom of its ramp?
1)
2)
3) both the same
Electric Energy
A proton and an electron are each
accelerated over the same distance
across a region of constant electric
field, E. Which experiences the
greater acceleration?
(1)
(2)
(3)
(4)
proton
electron
both have equal acceleration
neither, there is no acceleration at all
Electric Energy
A proton and an electron are each
accelerated over the same distance
across a region of constant electric
field, E. Which experiences the
bigger increase in Kinetic Energy?
(1)
(2)
(3)
(4)
proton
electron
both have the same increase in KE
neither -- KE = 0 for both
Work
Electric Potential Difference V =
q
PE
q
Electron Gun
Heated filament
Positively charged can
E = 800,000 N/C
d = 2.5 cm,
1e = 1.6010-19 C
vfinal?
Electric Potential
• Which point
has the
largest
potential?
1
3
+Q
2
4
5
Electric Potential
A
C
+Q
B
D
E
Which two points have the same potential?
(1) A and C
(3) B and D
(2) B and E
(4) C and D
(5) no pair
ConcepTest
+
If the electric potential at point A is Vo, then the
electric potential at point B is
1) ¼Vo
2) ½Vo
3) Vo
4) 2Vo
5) 4Vo
ConcepTest
+
If the electric potential at point A is Vo, then the
electric potential at point B is
1) ¼Vo
2) ½Vo
3) Vo
4) 2Vo
5) 4Vo
If the magnitude of the electric field at point A is
Eo, then the electric field at point B is
1) ¼Eo
2) ½Eo
3) Eo
4) 2Eo
5) 4Eo
Answers to preceding Multiple Choice questions
1) speed up.
2) down.
1) x  v0t  t  2.0 cm / v0
2) 50 J
2) 50 J
3) both the same
(2) electron
5) has the largest potential
(4) C and D
2) ½Vo
1) ¼Eo