An electrostatic paint sprayer has a potential of 25.0 kV that repels paint droplets onto a grounded object. What charge must a 0.63 mg drop of paint have to arrive at the object with a speed of 9 m/s? Give answer in terms of 10^-10 C.

10⁻⁶ C

Explanation:

Let the charge be Q

Gain of energy in electric field

= potential x charge

= 25 x 10³ x Q

Kinetic energy of droplet

=.5 x. 63 x 10⁻³ x 9 x 9

= 25.515 x 10⁻³ J

So, equating the energy gained

25 x 10³ x Q = 25.515 x 10⁻³

Q = 10⁻⁶ C