An electron of mass m₀, initially at rest, moves through a certain distance in a uniform electric field in time t₁. A proton of mass m_l, also, initially at rest, takes time t₂ to move through an equal distance in this uniform electric field. Neglecting the effect of gravity, the ratio t₂/t₁ is nearly equal to.

(m_p/m_c)^1/2

Electrostatic force, $F_e=e E$ (for both the particles) But acceleration of electron, a_e = F_e/m_e and acceleration of proton, $a_p i=F_e / m_p$

$S=\frac{1}{2} a_e t_1^2=\frac{1}{2} a p t_2^2$

∴ $\frac{t_2}{t_1}=\sqrt{\frac{a_e}{a_p}}=\sqrt{\frac{m_p}{m_e}} $