Question

A particular of mass m and charge q is thrown at a speed u against a uniform electric field E. How much distance will it travel before coming to momentary rest?

Answer 1

Given, U = velocity of prejection,
E = elecric field intensity
Q = charge,
m = mass of particle
we know, forc eexperience by a particle with hcarge e in an electric field = qe
aceleration produced $=\frac{qe}{m}$
So field, hence deceleration $=\frac{qe}{m}$
So, let the distance covered be s
Then $v^2=u^2+2$ as
[where a acceleration, v = final velocity]
Here $0=u^2-2a\times s\Rightarrow s=\frac{u^2}{2a}=\frac{m{u}^2}{2qe}$