Physics

Problem

A small particle of mass

m

and charge

-q

is projected directly away from a fixed positive charge

+Q

with speed

v_0

from an initial separation

r_0

. Neglecting all forces except the mutual electrostatic interaction, which expression gives the minimum value of

v_0

that will allow the particle to reach an infinite distance from

+Q

? a)

v_0 = \sqrt{\dfrac{kQq}{m r_0}}

v_0 = \sqrt{\dfrac{2kQq}{m r_0}}

v_0 = \sqrt{\dfrac{kQq}{2m r_0}}

v_0 = \sqrt{\dfrac{4kQq}{m r_0}}