<h2>
The magnitude of the force that acts on a charge of -7.9C at this spot is 2.21 x 10⁶ N.</h2>
Explanation:
Electric field is the ratio of force and charge.
Electric field, E = 280000 N/C
Charge, q = -7.9 C
We have

The magnitude of the force that acts on a charge of -7.9C at this spot is 2.21 x 10⁶ N.
Answer:
1/2 m v^2 + 1/2 I ω^2 = m g h conservation of energy
I = 2/5 m R^2 inertia of solid sphere
1/2 m v^2 + 1/5 m ω^2 R^2 = m g h
1/2 v^2 + 1/5 v^2 = g h
v^2 = 10 g h / 7 = 1.43 * 9.80 * 19 m^2/s^2 = 266 m^2/s^2
v = 16.3 m/s
v = R ω
ω = 16.3 / .6 = 27.2 / sec