Answer:

Explanation:
Let the charge on the ball bearing is q.
charge on glass bead, Q = 20 nC = 20 x 10^-9 C
Force between them, F = 0.018 N
Distance between them, d = 1 cm = 0.01 m
By use of Coulomb's law in electrostatics

By substituting the values


Thus, the charge on the ball bearing is 
wavelength of the EM wave produced by your iclicker is 0.33 m.
<h3>What makes an EM wave?</h3>
- When an electric field (illustrated in red arrows) combines with a magnetic field, electromagnetic waves are generated (which is shown in blue arrows). An electromagnetic wave's magnetic and electric fields are perpendicular to each other and to the wave's direction.
- A changing magnetic field causes a changing electric field, and vice versa—the two are inextricably related. Electromagnetic waves are created by changing fields. Electromagnetic waves, unlike mechanical waves, do not require a medium to propagate.
The clicker emits EM (electromagnetic) wave which travels at the speed of light, that is
v = 3 x 10⁸ m/s
The frequency is
f = 900mHz = 9 x 10⁸ Hz
velocity = frequency * wavelength, the wavelength, λ, is given by
fλ = v
λ = v/f
= (3 x 10⁸ m/s) / (9 x 10⁸ 1/s)
= 1/3 m = 0.333 m
To learn more about electromagnetic waves refer,
brainly.com/question/25847009
#SPJ1
The statement that is true of cooling down after physical activity is that you should cool down for about 5 to 10 minutes after being physically active.