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

The total electric force exerted by q₁ and q₂ on a charge q₃ is
`7*10^(-8)\ N`

Step-by-step 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)=(kq_(3)q_(1))/(r^2)`

Put the value into the formula

`F_(31)=(9*10^(9)*5*10^(-9)*2*10^(-9))/(1^2)`

`F_(13)=9*10^(-8)\ N`

For second force,

Using formula of electric force

`F_(32)=(kq_(3)q_(2))/(r^2)`

Put the value into the formula

`F_(31)=(9*10^(9)*5*10^(-9)*(-4*10^(-9)))/(3^2)`

`F_(13)=-2*10^(-8)\ N`

The total electric force is

`F=F_(31)+F_(21)`

`F=9*10^(-8)-2*10^(-8)`

`F=7*10^(-8)\ N`

Hence, The total electric force exerted by q₁ and q₂ on a charge q₃ is
`7*10^(-8)\ N`