- #1
brazen2
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Homework Statement
A charge of -4uC is fixed in place. From a horizontal distance of 55 cm, a particle of mass 0.0025kg and charge -3uC is fired with an initial speed of 15m/s directly towards the fixed charge. How far does the particle travel before it stops and begins to return back?
Homework Equations
KE=1/2mv^2
PE=qV
V=KQ/r
The Attempt at a Solution
KE=1/2mv^2
KE=1/2(0.0025kg )(15m/s)^2
KE= 0.28125
KE will equal PE when particle stops moving so...
PE=0.28125=qV=(-3e6)(9e9)(-4e6/r)
r= 0.384 = distance where particle stops moving
Is this correct? I don't want to use F= KQ1Q2/r^2 and F=ma for this question, as that would only give me the initial acceleration of the particle... Am I totally off track??
Thanks everyone