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By conservation of energy, the kinetic energy has to equal the change in potential energy, so KE=qV. The energy of the electron in electron-volts is numerically the same as the voltage between the plates. For example, a 5000-V potential difference produces 5000-eV electrons.

## Why is potential energy negative?

Gravitational potential energy is negative at the surface of Earth, because **work is done by the gravitational field in bringing a mass from infinity i.e work has to be done on a body, if it is taken away from the gravitational field of the earth**. Thus, potential energy is negative.

## Is electric potential positive or negative?

Note that the electrical potential energy is **positive if the two charges** are of the same type, either positive or negative, and negative if the two charges are of opposite types. This makes sense if you think of the change in the potential energy ΔU as you bring the two charges closer or move them farther apart.

## What is kinetic energy give example?

Kinetic energy is the energy of motion, observable as the movement of an object, particle, or set of particles. Any object in motion is using kinetic energy: **a person walking, a thrown baseball, a crumb falling from a table, and a charged particle in an electric field** are all examples of kinetic energy at work.