A 2.0 mm × 4.0 mm flat carpet acquires a uniformly distributed charge of −10 μC after you and your friends walk across it several times. A 3.0 μg dust particle is suspended in midair just above the center of the carpet.
a. What is the charge on the dust particle?

Respuesta :

Explanation:

Let us assume that the carpet is like a large sheet of charge for the dust particle.

Hence, the electric field is as follows.

                E = [tex]\frac{\sigma}{2 \epsilon_{o}}[/tex]

Now, the value of [tex]\sigma[/tex] will be as follows.

            [tex]\sigma = \frac{-10 \times 10^{-6}}{2 \times 4}[/tex]

                         = [tex]1.25 \times 10^{-6} C/m^{2}[/tex]

Now, for the dust particle

                [tex]F_{net} = F_{e} + mg[/tex] = 0

                         [tex]F_{e} = -mg[/tex]

                          qE = mg

Now, putting the given values into the above formula and calculate the charge as follows.

                qE = mg

           [tex]q \times \frac{1.25 \times 10^{-6} C/m^{2}}{(2 \times 8.854 \times 10^{-12} C^{2}/Nm^}{2})} = 3.0 \times 10^{-9} kg \times 9.8 m/s^{2}[/tex]

           q = [tex]416.49 \times 10^{-15} C[/tex]

Thus, we can conclude that charge on the dust particle is [tex]416.49 \times 10^{-15} C[/tex].