Introduction:
When an electric current flows through a metal, it is actually the movement of charge carriers, usually electrons, that constitutes the current. The velocity of these charge carriers can vary depending on various factors such as the material, temperature, and applied electric field.

Understanding current:
Current is defined as the rate of flow of charge through a conductor. It is measured in amperes (A), where 1 ampere is equivalent to 1 coulomb of charge passing through a point in a conductor per second. In other words, 1A means that 1 coulomb of charge flows through a point in a conductor every second.

Velocity of charge carriers:
The velocity of charge carriers in a metal under normal conditions is relatively low compared to the speed of light. This is because in a metal, the charge carriers, which are usually electrons, experience collisions with other atoms or impurities in the metal lattice. These collisions cause the electrons to lose some of their velocity and change direction, resulting in a random motion known as electron drift.

Typical velocities:
The velocity of charge carriers in a metal under normal conditions is typically of the order of a few millimeters per second or even less. This is significantly lower than the velocity of light, which is approximately 3 x 10^8 meters per second.

Reasons for low velocity:
1. Collisions: As mentioned earlier, the charge carriers experience collisions with other atoms or impurities in the metal lattice. These collisions hinder the movement of the electrons and reduce their average velocity.
2. Thermal motion: The charge carriers also undergo thermal motion due to their interaction with the lattice vibrations of the metal. This thermal motion adds randomness to their velocity and further reduces their net average velocity.

Conclusion:
In conclusion, the velocity of charge carriers in a metal under normal conditions, when a current of about 1A is flowing, is typically on the order of a fraction of millimeters per second. This low velocity is mainly due to the collisions and thermal motion experienced by the charge carriers in the metal. It is important to note that while the individual velocities of the charge carriers may be low, the overall current can still be significant due to the large number of charge carriers present in a conductor.