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louza8
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Homework Statement
An electron moves through an electric field, and its speed drops from 2900 {\rm m/s} to 1500 {\rm m/s} .
What's the potential difference between the two points at which the speed was measured?
Homework Equations
U=qV
K=mv^2/2
q=electron
m=mass of electron
The Attempt at a Solution
Ki=.5 * 9.109*10^-31 * 2900^2
= 3.83*10^-24J
Kf=.5 * 9.109*10^-31 * 1500^2
=1.0247*10^-24J
deltaK=2.80557*10^-24
p.d= deltaK/q
= 2.80557*10^-24/1.602*10^-19C
=1.8*10^-5V
Is it supposed to be negative 1.602*10^-19C for the charge on the electron and is that what is stuffing me up? Onto my final go of this on the online homework so trying to get it :)
Thanks for help in advance.