Question

A point charge with charge q1 = 3.40 μC is held stationary at the origin. A second point charge with charge q2 = -4.90 μC moves from the point ( 0.125 m , 0) to the point ( 0.280 m , 0.235 m ). How much work W is done by the electric force on the moving point charge?

Answer 1

-0.79 J

Step-by-step explanation:

We are given that

`q_1=3.4\mu C=3.4* 10^(-6) C`

`1\mu C=10^(-6) C`

`q_2=-4.9\mu C=-4.9* 10^(-6) C`

`x_1=0.125,y_1=0`

`x_2=0.280,y_2=0.235`

We have to find the work done by the electric force on the moving point charge.

`r_1=√(x^2_1+y^2_1)=√((0.125)^2+0)=0.125`

`r_2=√((0.280)^2+(0.235)^2)=0.366`

Work done,
`W=kq_1q_2((1)/(r_1)-(1)/(r_2))`

Where
`k=9* 10^9`

Using the formula

`W=9* 10^9* 3.4* 10^(-6)*(-4.9* 10^(-6))((1)/(0.125)-(1)/(0.366))`

`W=-0.79 J`