Question

particle of mass M and charge Q is thrown at a speed u against the electric field how much distance between travel before coming to momentary rest

Answer 1

as F= qe
ma=qe
a=qe/m
in y axis using equation of motion
s=ut+ 1/2at2
put value of a in above equation
in X axis
v=s/t
t=s/v put in equation 1
will get answer

Answer 2

Answer:$d=\frac{mu^2}{2Eq}$

Explanation:

Given

mass of charge is m and charge is q

Electric Field  is E

Now Force acting in Electric Field is given by F=Eq

Work done by Electric field=Eqd

where d is the maximum distance moved by charged particle

Change in Kinetic Energy is $\farc{mu^2}{2}$

Conserving energy to get d

$Eqd=\farc{mu^2}{2}$

$d=\frac{mu^2}{2Eq}$