If the effective field is E =800,000 N/C over a gap length of 2.5 cm, what is the electron’s final velocity, v ? Electron Gun Heated filamentPositively charged can (1.6  C)(8  10 5 N/C) 9.11  kg  0 + 2(1.405  m/s 2 )(0.025 m)   m 2 /s 2 v  8.38  10 7 m/s

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.

v o = 8.4  10 7 m/sec m e = 9.11  kg 1 e = 1.60  C E max = ? Electron Gun -e-e 2 centimeters 0.3 cm

2 centimeters 0.3 cm -e-e vo vo The time each individual electron spends between the two plates

2 centimeters 0.3 cm -e-e vo vo x = v ox t + ½a x t 2 y = v oy t + ½a y t 2 0 0

Concept Review h = 1 m A man lifts a 5 kg rock 1 meter off the ground. The potential energy of the rock is about A) 5 J B) 50 J C) 100 J D) 500 J About how much work did the man have to do? A) 5 J B) 50 J C) 100 J D) 500 J E) 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? A) B) C) 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) proton (2) electron (3) both have equal acceleration (4) 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) proton (2) electron (3) both have the same increase in KE (4) neither -- KE = 0 for both

Electric Potential Difference V = Work q  PE q

Which point has the largest potential?Which point has the largest potential? Electric Potential Q

Electric Potential Which two points have the same potential? (1) A and C (2) B and E (3) B and D (4) C and D (5) no pair A C B D E +Q

ConcepTest + If the magnitude of the electric field at point A is E o, then the electric field at point B is 1) ¼E o 2) ½E o 3) E o 4) 2E o 5) 4E o If the electric potential at point A is V o, then the electric potential at point B is 1) ¼V o 2) ½V o 3) V o 4) 2V o 5) 4V o

1) speed up. 2) down. 1) 2) 50 J 3) both the same (2) electron 5) has the largest potential (4) C and D 2) ½V o 1) ¼E o Answers to preceding Multiple Choice questions