A small bead of mass carrying an unknown charge is released from rest from a fixed charge

PHYSICS · Single correct · AP · Physics 2: Algebra-based · Electric Force Field and Potential · Electric Force Field and Potential

Problem

A small bead of mass

2.0\,\text{g}

carrying an unknown charge

q

is released from rest

1.20\,\text{m}

from a fixed charge

q_1 = +5.0\,\mu\text{C}

. When the bead reaches

0.40\,\text{m}

from

q_1

, its speed is

30\,\text{m}\,\text{s}^{-1}

. Assuming no non-conservative forces act, what is the charge

q

on the bead? (a)

+12\,\mu\text{C}

(b)

-24\,\mu\text{C}

(c)

-12\,\mu\text{C}

(d)

+25\,\mu\text{C}