A particle of mass carries a charge of

PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

A particle of mass

1.0\,\text{mg}

carries a charge of

+1.0\,\text{nC}

. It is launched from the origin with a speed of

0.50\,\text{m/s}

directly along the

+x

-axis. The electric potential along this axis is given by

V(x)=4x^{2}

, where

x

is in meters and

V

in volts. Neglecting all forces other than the electric force, at what

x

-coordinate will the particle momentarily come to rest before reversing direction? (a)

11\,\text{m}

(b)

5.6\,\text{m}

(c)

7.9\,\text{m}

(d)

4.0\,\text{m}