In a spherical metal shell of radius R, an electron is shot from the center directly toward a tiny hole in the shell, through which it escapes. The shell is negatively charged with a surface charge density (charge per unit area) of 8.80 × 10-13 C/m2.
What is the magnitude of the electron's acceleration when it reaches radial distances (a) r = 0.620 R and (b) 2.00R?.