A particle (charge 7.5 µC) is released from rest at a point on the x axis, x = 10 cm. It begins to move due to the presence of a 2.0-µC charge which remains fixed at the origin. What is the kinetic energy of the particle at the instant it passes the point x = 1.0 m?

1.215J

Explanation:

Using the law of energy conservation, the potential energy is equal to the kinetic energy of the particle during motion:

#the V of the 2.0-µC is expressed as:

We substitute the given values from the question:

##When the moving charge reaches 0.1meter the energy becomes

#When the moving charge reaches 1.0 meter the energy becomes

Hence, the change in energy is

the answer is 12 as i may remember

: )