Question

Two point charges are located on the x-axis of a coordinate system; q1 = 2 nC is at x = 1 cm, and q2 = -4 nC is at x = 3 cm. What is the total electric force exerted by q1 and q2 on a charge q3 = 5 nC at origin?

Answer 1

Answer:

The total electric force exerted by q₁ and q₂ on a charge q₃ is $7\times10^{-8}\ N$

Explanation:

Given that,

First charge $q_{1}=2 nC$

Distance = 1 xm

Second charge  $q_{2}=-4 nC$

Distance = 3 cm

Charge at origin $q_{3}=5\ nC$

We need to calculate the total electric force exerted by q₁ and q₂ on a charge q₃

For first force,

Using formula of electric force

$F_{31}=\dfrac{kq_{3}q_{1}}{r^2}$

Put the value into the formula

$F_{31}=\dfrac{9\times10^{9}\times5\times10^{-9}\times2\times10^{-9}}{1^2}$

$F_{13}=9\times10^{-8}\ N$

For second force,

Using formula of electric force

$F_{32}=\dfrac{kq_{3}q_{2}}{r^2}$

Put the value into the formula

$F_{31}=\dfrac{9\times10^{9}\times5\times10^{-9}\times(-4\times10^{-9})}{3^2}$

$F_{13}=-2\times10^{-8}\ N$

The total electric force is

$F=F_{31}+F_{21}$

$F=9\times10^{-8}-2\times10^{-8}$

$F=7\times10^{-8}\ N$

Hence, The total electric force exerted by q₁ and q₂ on a charge q₃ is $7\times10^{-8}\ N$