what is the acceleration

Question

The electrons that produce the picture in a TV set are accelerated by a very large electric force as they pass through a small region in the neck of the picture tube. This region is 1.5 cm in length, and the electrons enter with a speed of 1 × 105 m/s and leave with a speed of 2.5 × 106 m/s. What is their acceleration over this 1.5 cm length? Answer in units of m/s 2

Answer 1

Use the kinematic relation

vf^2 - vi^2 = 2ad

a = (vf^2 - vi^2) / (2d)

Plug in the following numbers and get your answer in m/s^2:

vf = 2.5 x 10^6 m/s

vi = 1 x 10^5 m/s

d = 0.015 m