Particle physics problem

Question

A meson, a subatomic particle having a mass 250 times that of an electron, is shot with a constant speed of 5.00 x 10⁶ m/s into a region where an electric field causes a deceleration of 1.25 x 10¹⁴ m/s².

(a) How far does the meason travel before coming to rest?

(b) How long does it take the meson to come to rest?

Answer 1

(a) 0² - v² = 2as, s = - v²/2a = - (5·10⁶m/s)²/(- 2·1.25·10¹⁴m/s²) = 0.1 m

(b) 0 = v + at; t = - v/a = - 5·10⁶m/s/(- 1.25·10¹⁴m/s²) = 4·10^-8 s