Kinetic energy and temperature

The term kinetic energy can be defined as the energy that is possessed by an object due to motion. It is, therefore, the force needed to make an object accelerate which has a particular mass to its required velocity. When the body gains this energy from acceleration, it maintains this energy until an external speed is applied to it. This form of energy not only depends upon the motion of the object but also depends upon its mass.

When kinetic energy is being transferred between objects, it gets transformed into other forms of energy. The kinetic energy of wind gets transformed into electricity through a number of steps, in wind turbines. 

Kinetic energy and temperature

The relationship between kinetic energy and temperature is that the higher the temperature, the faster the movement of the particles. The only motion possible for atoms in a simple monatomic gas, such as helium or neon, travels from one location to another in a straight line until they collide with another atom or molecule. So, a gas’s average kinetic energy and temperature are directly proportional. The relative kinetic energy of the two colliding atoms can and often does change as a result of these collisions: if one slows down, the other accelerates. 

Kinetic energy

The kinetic energy of an atom or molecule is directly proportional to the temperature in translational motion. 

So,

KE = 1/2mv² = 3/2 kT, 

where v = the average velocity of the population’s molecules

m denotes mass

k = the Boltzmann constant

T = temperature 

Atoms in any given gaseous sample collide multiple times in unit time. Yet, these collisions do not affect the total energy of the system.

There is kinetic energy in every atom and molecule, but not temperature. This is a crucial distinction to make. Individual molecules do not have a temperature; they have kinetic energy. Populations of molecules have a temperature linked to their average velocity. While a system’s temperature is constant, the kinetic energy of the individual molecules that make up the system might vary. Even though the temperature of the system remains constant, an individual molecule’s kinetic energy might change rapidly due to collisions between molecules. Individual kinetic energy will be crucial when it comes to chemical bonds.

How do we define temperature?

Temperature is a measure of how hot or cold something is. More specifically, it is a measure of the average kinetic energy of an object. But when it comes to hot and cold, how much hot is hot and how much cold is cold? The terms “hot” and “cold” aren’t scientific. Their intensities, represented by temperature, must be used if we want to precisely indicate how hot or cold something is. How hot is molten iron, for example? A physical scientist would measure the temperature of the liquid metal to answer that. Using temperature instead of phrases like hot or cold helps avoid misunderstandings.

Units of kinetic energy

The kinetic energy of a body that gets transferred is equal to the product of the mass and square of the velocity when divided by 2. Therefore, the formula for kinetic energy can be written as:

                                 K.E= (½)mv²

The above formula is often valid just for the cases of transfer from low to relatively higher speeds. Except for extremely high-speed particles, it gives negligible values. When the speed of an object proceeds towards that of light (3 × 108 metres per second, or 186,000 miles per second), we can observe an increase in its mass and the laws of relativity come into play. The relativistic kinetic energy is equal to the rise in the mass of a particle at rest when multiplied by the square of the speed of light.

The unit of kinetic energy in the metre-kilogram-second system is represented as joule. A two-kilogram mass (approximately 4.4-pound weight on earth) moving at a speed of 1m/s encompasses a KE of 1 joule. But in the centimetre-gram-second system, the unit of kinetic energy is represented in erg. There are also some other units of energy that are used, like the eV, which is used in the atomic and subatomic scale.

Conclusion

According to the kinetic-molecular theory, a substance’s temperature is proportional to the average kinetic energy of its particles. When a substance is heated, some of the absorbed energy is stored inside the particles, while the rest of the energy is used to accelerate particle motion. This is manifested as an increase in the substance’s temperature. The relationship between kinetic energy and temperature is that the higher the temperature, the faster the particles move.