Problem: A spring with an unstrained length of 0.071 m and a spring constant of 2.3 N/m hangs vertically downward from the ceiling. A uniform electric field directed upward fills the region containing the spring. A sphere with a mass of 5.0 x 10-3 kg and a net charge of +5.8 μC is attached to the lower end of the spring. The spring is released slowly, until it reaches equilibrium. The equilibrium length of the spring is 0.063 m.
Part I: What is the magnitude of the external electric field?
I need help to find the magnitude of the external electric field.