- #1
godmoktail
- 7
- 0
Homework Statement
Homework Equations
F = | kqQ / r*r |
The Attempt at a Solution
Magnitude:
F_net = F_1on3 + F_2on3
F_1on3 = (9E9)(70E-6)(15E-6) / ( (sqrt(5))^2 ) = 1.89N
F_2on3 = (9E9)(-36E-6)(15E-6) / ( (2)^2 ) = -1.215N ~ -1.22N
F_net = 1.89 - 1.22 = 0.67N
Direction = arctan(F_y/F_x)
In component form the vectors for r_13 and r_23 are:
r_13 = 2i + 1j && r_23 = 2j
Therefore the force in component notation would be:
Fvec_13 = 1.89(2i + 1j) = 3.78i + 1.89j
Fvec_23 = -1.22(2j) = -2.44j
Fvec_net = 3.78i - 0.55j
Thus angle must be:
theta = arctan(-0.55/3.78) = -8.13 degrees
I entered 0.675 for the magnitude and was told it was incorrect, although I'm positive I did the work correctly. Am I wrong? (I am a little unsure about the angle part)
Thanks in advance.