In picture tubes of color televisions, electrons pass an accelerating potential

In picture tubes of color televisions, electrons pass an accelerating potential difference of 35 kV. At what speed do electrons fly up to the CRT screen?

These tasks: φ1 – φ2 (accelerating potential difference in the tube) = 35 kV (35 * 10 ^ 3 V).

Constants: qe (modulus of charge of one electron) = 1.6 * 10-19 C; me (electron mass) = 9.1 * 10 ^ -31 kg.

The speed at which the electrons fly up to the CRT screen is determined from the equality: (φ1 – φ2) * qe = me * V ^ 2/2, whence V = √ (2 * (φ1 – φ2) * qe / me).

Calculation: V = √ (2 * 35 * 10 ^ 3 * 1.6 * 10 ^ -19 / (9.1 * 10 ^ -31)) = 111 * 10 ^ 6 m / s.

Answer: The electrons will fly up to the CRT screen at a speed of 111 * 10 ^ 6 m / s.