A negative ion with mass m m\,m and charge −2e-2e−2e is released in a region with a uniform electric field. The ion is observed to have an acceleration of magnitude a a\,a in the positive zzz-direction. Assuming gravitational effects are negligible, what is the magnitude and direction of the electric field in this region?
Magnitude 2eam\frac{2ea}{m}m2ea in the positive zzz-direction
Magnitude ma2e\frac{ma}{2e}2ema in the positive zzz-direction
Magnitude ma2e\frac{ma}{2e}2ema in the negative zzz-direction
Magnitude 2eam\frac{2ea}{m}m2ea in the negative zzz-direction
