Final answer:
The voltage required to accelerate a positive charge between two parallel plates is called the potential voltage, and it relates to the energy needed to move a charged particle within an electric field.
Step-by-step explanation:
To accelerate a positive charge between two parallel plates to a specified speed, the required voltage is known as the potential difference or potential voltage. This term refers to the difference in electric potential between two points in an electric field, which provides the energy needed to move a charged particle, such as an electron or a proton, from one point to another. The kinetic energy acquired by the charge is numerically equal to the product of the charge and the potential difference (KE = qV), and thus, the voltage required to accelerate a charge can be determined by rearranging this equation (V = KE/q). If the charge is being accelerated from rest, the kinetic energy (KE) would be equal to ½ mv² where 'm' is the mass, and 'v' is the velocity of the charge. In the context of an electron gun or a Van de Graaff accelerator, this energy is often expressed in electron-volts (eV), where 1 eV is equivalent to the energy gained by an electron when it is accelerated through a potential difference of 1 volt.