The charge on each of the equally charged drops of hairspray willl be 7 × 10 ⁻¹³ C
<h3>What is Columb's law?</h3>
The force of attraction between two charges, according to Coulomb's law, is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
Similar charges repel each other, whereas charges that are opposed attract each other.
Given data;
Electric force,F = 9 × 10 ⁻⁹ N
Distance between charges,d = 7 × 10⁻⁴ m
Chrge,q₁ = q₂ =q C
From Columb's law;

Hence the charge on each of the equally charged drops of hairspray willl be 7 × 10 ⁻¹³ C
To learn more about Columb's law refer to the link;
brainly.com/question/1616890
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The speed of sound at

is approximately v=343 m/s. The distance covered by the sound wave is

And the time it takes is

Now we want to find how far the light travels during this time. Light travels at speed

, therefore the distance it covers during this time is
consider the velocity of the ball towards the wall as negative and away from the wall as positive.
m = mass of the ball = 513 g = 0.513 kg
v₀ = initial velocity of the ball towards the wall before collision = - 14.7 m/s
v = final velocity of the ball away from the wall after collision = 11.3 m/s
t = time of contact with the wall = 0.038 sec
F = average force acting on the ball
using impulse-change in momentum equation , average force is given as
F = m (v - v₀)/t
inserting the values
F = (0.513) (11.3 - (- 14.7))/0.038
F = 351 N
The acceleration of gravity on Earth is 9.8 m/s² downward.
This means that gravity adds 9.8 m/s downward to the speed
of a freely falling object every second.
So after 25 sec, it's falling (25 x 9.8m/s) = 245 m/s faster than
it was falling at the beginning of the 25 seconds.
If it dropped from rest (no speed), then its velocity
after 25 seconds is 245 m/s downward.