Shalymar Usman
BSIT2 B1
1. Three point charges are arranged along x-axis as follows: charge q = 3.0 µC is
at the origin, and charge q = - 5.00 µC is at x = 0.200 m. Charge q = -8.00 µC.
Where is q located if the net force on q1 is 7.00 N in the -x-direction?
Note: Show your free body diagram (FBD) and solutions accurately,
systematically and orderly with the standard unit, and express it into
prefix word if possible.
1
2
3
3
Fnet = -7i
= F12 + F13
F12 =
𝑘𝑞1 𝑞2
2
𝑟
12
=
9 x 109 x 3 x 10−6 x 5 x 10−6
4 𝑥 10−2
= 33.75 x 10-1 N
F12 = 3.375 I (N)
F13 = Fnet – F12 = - 7i – 3.375 I = - 10.375i (N)
2
r13 =
𝑘𝑞1 𝑞2
𝐹12
=
9 x 109 x 24 x 10−12
10.375
= 0.0208m2
r13 = 0.144 m