A particle that carries a charge `-q` is placed at rest in uniform electric field `10N//C` .It experiences a force and moves .In a certain time 't' it is observed to acquire a velocity `10bar(i)-10bar(i)m//s` The given electric field intersects a surface of area `1m^(2)` in the `x-z` plane .Find the Electric flux through the surface.

Explanation

Force on charge `bar(F)=qbar(E)`
`:.` Particle moves opposite to `bar(E)` with `bar(V)`
unit vector in the direction of `bar(V)` is `(bar(i))/(sqrt(2))-(bar(j))/(sqrt(2))`
unit vector in the direction of `vec(E)` is `(bar(i))/(sqrt(2))-(bar(j))/(sqrt(2))`
`bar(E)=10[(-i)/(sqrt(2))+(j)/(sqrt(2))] i.e,bar(A)=1xxbar(j)`
Electric fulx `phi=bar(E).bar(A)=5sqrt(2)Nm^(2)//C`