Aparticle with charge 3 µc is located on the x-axis at the point −10 cm , and a second particle with charge −5 µc is placed on the x-axis at 6 cm . −10−8 −6 −4 −2 2 4 6 8 10 3 µ c − 5 µ c − 7 µ c x → (cm) what is the magnitude of the total electrostatic force on a third particle with charge −7 µc placed on the x-axis at 2 cm ? the coulomb constant is 8.9875 × 109 n · m 2 /c 2 . answer in units of n.

Force on -7 uC charge due to charge placed at x = - 10cm

now we will have

towards left

similarly force due to -5 uC charge placed at x = 6 cm

now we will have

towards left

Now net force on 7 uC charge is given as

towards left

i think it’s a. this is because if they measured the mass of something with a mass of 150g, then their final answer would have to be approximately 150g. though all of their answers are almost 150, rosa and tran have the closest answers (or the exact answer) to the accurate one.