Answer 8_1_3
|
Calculate the kinetic energy and speed of an electron where the anode voltage is (a) 400 V (b) 400 kV |
|
(a) Ek
= eV = 1.6 ´
10-19 ´ 400 V = 6.4 ´ 10-17J |
|
v2
= eEk/m = 2 ´ 6.4 ´ 10-17J ¸
9.11 ´
10-31 kg = 1.41 ´
1014 m2 s-2 |
|
v
= 1.18 ´
107 m/s |
|
(b) Ek
= eV = 1.6 ´
10-19 ´ 400 000 V = 6.4 ´
10-14J |
|
v2
= eEk/m = 2 ´ 6.4 ´ 10-14J ¸
9.11 ´
10-31 kg = 1.41 ´
1017 m2 s-2 |
|
v
= 3.74 ´
108 m/s |
|
|