Question

Burning coal, which is how many power plants generate electricity, releases a number of harmful byproducts. Particulate pollution (i.e., soot or smoke) is the most visually obvious. Modern coal-burning power plants make use of electrostatic precipitators (ESPs) to remove most of the particulate pollution. As the hot, impure air heads out of the plant, it passes through an area where soot particles can pick up some electric charge. The air then passes through an area with a strong electric field to pull the pollutant particles away to an area where they can be safely removed.
Suppose that a charged particle of diameter 1.00 micrometer moves with constant speed in an electric field of magnitude 1.00×105 newtons per coulomb while acted upon by a drag force of 7.25×10−11 newtons. What is the charge q1 on the particle? Ignore the effects of gravity.

Express your answer in coulombs to three significant figures.

Answer 1

Answer:

$7.25\times 10^{-16}\ C$

Explanation:

F = Force = $7.25\times 10^{-11}\ N$

E = Electric field = $1\times 10^5\ N/C$

Force is given by

$F=qE$

$\Rightarrow q=\dfrac{F}{E}$

$\Rightarrow q=\dfrac{7.25\times 10^{-11}}{1\times 10^5}$

$\Rightarrow q=7.25\times 10^{-16}\ C$

The charge on the particle is $7.25\times 10^{-16}\ C$