A particle 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?

Options

A. `(2m u^(2))/(qE)`
B. `(m u^(2))/(qE)`
C. `(m u^(2))/(2qE)`
D. `(m u^(2))/(2 qE)`

Answer

4

Explanation

Retardation `a = (qE)/(m)`
`v^(2) = u^(2) - 2as`
`0 = u^(2) - (2qE)/(m) s`
`s = (mu^(2))/(2 qE)`