In: Physics
Two 2.0-cm-diameter insulating spheres have a 5.60 cm space between them. One sphere is charged to + 40.0 nC , the other to - 60.0 nC .
Part A
What is the electric field strength at the midpoint between the two spheres?
Given:
diameter of spheres d = 2.0cm
radius of the spheres r = d/2
= 1cm
= 1*10^-2 m
charge on sphere 1 q1 = 40*10^-9 C
charge on sphere 2 q2 = -60 *10^-9 C
distance between the spheres d = 5.60*10^-2 m
midpoint p
=2.80*10^-2 m
Electric field strength due to sphere1 at point p
total distance to point p = (2.80*10^-2)+ 1*10^-2
=3.8*10^-2 m
Electric field E1 = kq1/r^2.......(1)
= (9*10^9)(40*10^-9)/(3.8*10^-2)^2
= 24.9*104N/C
Electric field strength due to sphere 2 at point p
total distance to point p = (2.8*10^-2)+ 1*10^-2
= 3.8*10^-2 m
Electric field E2 = kq2/r^2.......(1)
= (9*10^9)(60*10^-9)/(3.8*10^-2)^2
= 37.4*104 N/C
total electric field strength at point p E = E1+E2
= 62.3*104N/C
˜62.3*104N/C