Kinetic energy=1/2mv^2
=1/2(142*10^-3)(42.9)^2=130.6=131J
Answer:
y = 10.2 m
Explanation:
It is given that,
Charge, 
It is placed at a distance of 9 cm at x axis
Charge, 
It is placed at a distance of 16 cm at x axis
We need to find the point on the y-axis where the electric potential zero. The net potential on y-axis is equal to 0. So,

Here,

So,

Squaring both sides,

So, at a distance of 10.2 m on the y axis the electric potential equals 0.
Answer:
When an electric field exists in a conductor a current will flow.
This implies a voltage difference between two points on the conductor.
Electrostatics pertains to static charge distributions.
That means that an object such as a charged spherical conductor will be at the same potential (voltage) on both its outer and inner surfaces.
If the distance between two charges is halved, the electrical force between them increases by a factor 4.
In fact, the magnitude of the electric force between two charges is given by:

where
k is the Coulomb's constant
q1 and q2 are the two charges
r is the separation between the two charges
We see that the magnitude of the force F is inversely proportional to the square of the distance r. Therefore, if the radius is halved:

the magnitude of the force changes as follows:

so, the force increases by a factor 4.