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Pascal - Unit of Energy Measurement

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Last updated date: 23rd Jul 2024
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What Is Pascal?

The pascal is symbolized as Pa. It is the SI-derived unit of pressure that is used to quantify internal pressure, stress, Young's modulus, and tensile strength. The unit Pascal is named after the French mathematician, physicist, religious philosopher, and master of prose Blaise Pascal.

In the CGS System, Pascal is defined as one newton per square meter and it is equivalent to 10 baryes (Ba).

In this article, we will learn about the Pascal unit of energy measurement, unit of energy measurement, and unit of measurement of energy in detail.

What is Energy?

The word ‘Energy’ is derived from the Latin word Energeia and the Greek word Ενεργεια. It is a measure of the ability to do mechanical work.

Energy is a fundamental concept relating to the ability to act. 

In physics, it is a quantity that every physical system possesses; this quantity is not absolute; however, relative to a state of the system, also known as its reference state or reference level. 

The energy of a physical system is the amount of mechanical work that the system can generate if it changes its state to its reference state; for example, if two liters of water cool to 0°C or if a car hits a stone and decelerates from 120 km/h to 0 km/h.

Now, let us understand the energy and its types:

Types of Energy

Energy can be in several forms:                    

  1. Mechanical Potential - A mechanical potential energy is a possible physical interaction with other objects (for example, gravitational potential energy, mechanical energy).

  2. Kinetic Potential - This energy is contained in macroscopic motion; such as the motion of a car, a ball, and so on.

  3. Chemical - A potential stored in chemical bonds between atoms and molecules.

  4. Electrical - Am electrical potential due to charge interactions

  5. Thermal - The energy contained in the kinetic energy of individual molecules

  6. Nuclear Energy - Potential stored between components of the atomic nucleus. Light can be viewed as energy in the form of photons/waves, depending on the context. 

The theory of general relativity (given by Einstein) provides a framework for visualizing mass itself as an expression of energy.

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Unit of Energy Measurement

The official unit of energy measurement is Joule (J). It is the most common unit for measuring energy. In electrical terms, the unit of energy measurement is kilowatt/hour or kWh, used especially for electric energy. The other units MegaJoule, Watt-hour, etc.

Do You Know?

The unit Kilowatt Per Hour unit of energy measurement is used to calculate electricity bills.

Units of Measurement of Energy

As we know that energy is the ability to do work, i.e. energy produces work. According to the second law of thermodynamics, whenever the work is done by absorbing the energy viz: heat from the reservoir, some heat is always rejected to the sink (surrounding). Work and heat are the forms of energy; thus the units of measurement of energy, work, and heat are the same.

Numerous energy measurement systems exist at present but the most commonly used system is the International Systems or SI. Below are the units of measurement of energy, work, and heat in various systems:

1. MKS system (Metric system): 

MKS unit is the most commonly used unit to indicate the energy content of the fuel and food, the heat-storing capacity in a reservoir, the capacity of refrigeration, and air-conditioning system, etc. 

2. Calories or Cal: 

One calorie is the amount of heat required to raise the temperature of 1 gram of water by one degree Celsius. Calorie is a very small unit and the larger unit of the same is Kilocalories or Kcal. Kcal is also more commonly used unit. 1Kcal = 1000 cal.

3. SI unit System: 

Joule: The SI system is also the most commonly used unit. Joule unit has been named in honour of the physicist James Prescott Joule (1818–1889). Joule who has made very important contributions in the field of thermodynamics, especially in work and energy. 

Joule is a derived unit that is defined as the work done, or energy required to exert a force of one newton on the object for a distance of one meter, so the same quantity may be referred to as a newton meter or newton-meter or simply N.m/N-m.

Even Joule is a small unit; hence, for large units, kilo Joule or KJ is used commonly. 1KJ = 1000J.

4. British Thermal unit: 

Btu: One Btu is the energy required to raise the temperature of one pound of water by one degree Fahrenheit.

FAQs on Pascal - Unit of Energy Measurement

Q1: Define One Joule.

Ans: One Joule is the amount of energy required to complete a task. One Joule or 1 Joule can be written as kg·m2·s−2. However, the newton meter is usually used as a measure of torque, not energy. In other terms, we define One Joule in the following manner:

  • The amount of work required to move an electric charge of one coulomb through an electrical potential difference of one volt; or one coulomb volt, with the symbol C·V.

  • The work done to produce power of one watt continuously for one second, or one watt second or compare kilowatt-hour, with the symbol W·s, kW-h, respectively.

Q2: Describe the Conservation of Energy.

Ans: Conservation of energy is the transformation of one form of energy into another.

For instance, your inverter battery converts chemical energy into electrical energy, which is utilized when the power goes off. This energy in turn can be transformed into thermal energy. 

Similarly, the potential energy of moving water is converted into kinetic energy that rotates a turbine in a dam, this energy, in turn, transforms into electric energy by the generator. 

So, the law of conservation of energy states that in a closed system the total amount of energy, corresponding to the sum of a system's energy components, always remains invariant. This law of conservation of energy follows the translational symmetry of time, which states the independence of any physical process on the moment or the time it is initiated.