Answer:
2.39 * 10^5 N/C
Explanation:
Given that:
q1 = 7.1 nC = 7.1 * 10^-9 C
q2 = - 2.0 nC = 2 * 10^-9 C
Distance (d) = 3.7 cm apart
Hence, midpoint (r) = 3.7/2 = 1.85 cm = 1.85/100 =0.0185 m
The electric field strength at midpoint is given by:
E = k/r² ( q1 + q2)
K = 9.0 * 10^9
E = ((9 * 10^9) / 0.0185^2) * (7.1 * 10^-9 + 2 * 10^-9)
E = (2.62965 * 10^13) * (9.1 * 10^-9)
E = 23.929815 * 10^13 - 9
E = 23.929815 * 10^4
E = 2.39 * 10^5 N/C