Final answer:
The average kinetic energy of a substance's particles is based on their motion and temperature, with most particles having kinetic energies near the average. Temperature influences both the average kinetic energy and the range of kinetic energies among particles.
Step-by-step explanation:
The average kinetic energy of the particles within a substance can be described by looking at their motion, which is constant and random, directly dependent on the temperature of the substance. Individual particles of a substance, such as the 5000 particles mentioned, would have a range of kinetic energies, with most having an energy amount close to the middle of this range. The important aspect to remember is that the average kinetic energy is representative of the substance's temperature, meaning at the same temperature, all substances' particles share the same average kinetic energy.
Moreover, this average can also be influenced by the mass and velocity of the particles, as kinetic energy is defined as one-half the product of the particle's mass and the square of its speed. Hence, with increased temperature, not only does the average kinetic energy rise, but the distribution of individual kinetic energies broadens, indicating a greater diversity in particle speeds.
Therefore, understanding the motion and energy of particles provides valuable insight into the thermal behavior of matter. Particles vibrating quickly have a higher average kinetic energy, which correlates to what we term as 'hot'. Conversely, particles moving slowly demonstrate lower average kinetic energy, implying the object is 'cold'.