Skip to main content

Illustration Relationship between voltage and kinetic energy

Relationship between voltage and kinetic energy
Relationship between voltage and kinetic energy Voltage between minus and plus pole
Download illustration

Share — copy and redistribute the material in any medium or format

Adapt — remix, transform, and build upon the material for any purpose, even commercially.

Sharing and adapting of the illustration is allowed with indication of the link to the illustration.

A positively charged box (plus pole) with the charge \(Q\) is located at a certain distance from a negatively charged box (minus pole) with the charge \(Q\). A small test charge \(q\) is placed near the positive box. This test charge experiences an attractive force in the direction of the negatively charged box. It is accelerated and reaches a certain speed at the negative box. Thus the test charge has gained kinetic energy \(W\). If you divide this energy by the test charge \(q\), you get the voltage \(U\) between the two poles:\[ U ~=~ \frac{W}{q} \]

Voltage is the energy (per charge) gained by the test charge as it travels the distance between the positive and negative poles.