4) 2 charges of +4.0x10^-6 C and +8.0x10^-6 C are placed 2.0m apart. What is the field strength halfway between them?
[I got an answer of 3.6x10^4N/C toward the 4.0x10^-6C charge, but the answer given is 3.6x10^-4N/C toward the larger charge]
5) A point charge of 2.0x10^-6C experiences an electric force of 7.5N to the left. What force would be exerted on a -4.9x10^-5 C charge placed at the same spot?
[My answer is 1.8x10^2N[right], but the answer given is 1.5x10^5N/C[left] ]
6)
[I got 3.2x10^5N/C [right], but the answer in the book is 1.8x10^5N/C[right] ]
