The voltage between the cathode and the screen of a computer monitor is 12 kV.If we assume a speed of zero for an electron as it leaves the cathode,what is its speed just before it hits the screen? A)8.8 × 10⁷ m/s B)6.5 × 10⁷ m/s C)4.2 × 10¹⁵ m/s D)7.7 × 10¹⁵ m/s E)5.3 × 10⁷ m/s

Question

Quizplus · Accepted Answer

The kinetic energy gained by the electron is equal to the electric potential energy, which is eV. Using the equation $ \frac{1}{2}mv^2 = eV $, where e is the charge of an electron and V is the voltage, we can solve for v, the speed of the electron. Substituting the known values gives approximately 6.5 × 10^7 m/s.

The Voltage Between the Cathode and the Screen of a Computer