Name: energy forms and conservation
Uploaded: 2020-09-03T13:38:25.000Z
Duration: 4 min 10 s
Channel: JoVE

K12 Standards

Pennsylvania State Academic Standards

9-12

Physical Science

Energy

3.2.9-12.Q

What is Energy?

La energía se define como la capacidad de producir trabajo. El trabajo se define como la distancia recorrida por un cuerpo como respuesta a una fuerza que se le aplica. Por ejemplo, cuando se levanta un libro del suelo y se pone sobre la mesa, se produce trabajo contra la fuerza de gravedad.La energía se clasifica en dos tipos principales:potencial y cinética. La energía potencial es la energía asociada con la posición, composición o condición de un cuerpo. También se le conoce como energía en reposo o energía almacenada.Por ejemplo, el libro que está sostenido sobre el suelo, en la mesa, tiene energía potencial debido a la altura en la que se encuentra. Esta energía potencial se mantiene almacenada en el libro mientras esté sostenido en esa posición. Entre las distintas formas de energía potencial se encuentran la energía potencial gravitatoria, la energía potencial eléctrica, la energía potencial química, la energía nuclear y la energía elástica.La energía potencial gravitatoria es la forma más evidente de energía potencial, y depende de la posición relativa del cuerpo bajo la influencia del campo gravitacional. Por ejemplo, el libro que se sostiene sobre la mesa tiene energía potencial gravitatoria almacenada en él. La energía potencial eléctrica resulta de la atracción o repulsión de cargas eléctricas, como en el caso de la energía almacenada dentro de un condensador en un circuito eléctrico, la cual se encuentra en forma de energía potencial eléctrica.La energía potencial química es la energía almacenada en las moléculas. Por ejemplo, la madera seca almacena energía potencial química, la cual se libera y se convierte en otras formas de energía cuando la madera se quema. La energía nuclear proviene del núcleo atómico.y la energía elástica es la que está almacenada en un cuerpo debido a su configuración, como en el caso de una resortera estirada. La energía cinética es aquella asociada con el movimiento de un cuerpo. Por ejemplo, cuando el libro se cae de la mesa, su energía potencial se convierte en energía cinética debido al movimiento.La energía cinética también existe en distintas formas, Como la energía mecánica, eléctrica, térmica y radiante. Mientras que la energía mecánica se debe al movimiento mecánico de un cuerpo, como un auto en movimiento, la energía eléctrica está formada por el flujo de cargas eléctricas, como en los relámpagos. Cuando la energía cinética está en forma de ondas electromagnéticas, como la energía de la luz solar, esta se convierte en energía radiante.La energía térmica es la energía cinética asociada con el movimiento de los átomos y moléculas en un cuerpo. Cuando los átomos y moléculas dentro de un cuerpo se mueven o vibran rápidamente y colisionan con más frecuencia entre ellos, la temperatura del cuerpo aumenta. El calor de una llama ardiente es un ejemplo de energía térmica.Lo contrario sucede cuando las vibraciones o movimientos de estos átomos y moléculas se ralentizan. Entonces, se dice que el cuerpo está frío y tiene una energía térmica baja, como cuando el agua se congela. Todas estas diferentes formas facilitan el flujo de energía de un tipo a otro, o de un cuerpo a otro, para realizar el trabajo.La ley de conservación de la energía postula que la energía no se crea ni se destruye, solo se transforma en otros tipos de energía. Por lo tanto, la cantidad de energía total del sistema se conserva. En el tiro con arco, por ejemplo, una flecha sostenida en un arco estirado contiene energía potencial elástica.Cuando el arco se suelta, esta energía potencial se convierte en energía cinética de la flecha y esta es impulsada hacia adelante para dar en el blanco. De nuevo, la energía total permanece invariable.

¿qué es la energía?

El universo está compuesto de materia en diferentes formas y todas las formas de materia contienen energía.  Las diferentes formas de energía en la Tierra provienen del Sol — la última fuente de energía. Las plantas capturan la energía lumínica del Sol y, a través del proceso de fotosíntesis, la convierten en energía química. Esta energía almacenada de las plantas puede ser aprovechada de muchas maneras. Por ejemplo, comer productos vegetales como alimento proporciona energía para que nuestro cuerpo funcione y quemar madera o carbón (plantas fosilizadas) genera calor y electricidad. Por lo tanto, como todos los cambios de la materia implican cambios en la energía, es vital entender cómo fluye la energía de una forma a la otra. 
 
 La energía se define como la capacidad de hacer trabajo. El trabajo se realiza cuando una fuerza aplicada a un objeto hace que el objeto se mueva en contra de una fuerza opuesta. Por ejemplo, se realiza trabajo cuando se empuja una mesa a través de una habitación contra la resistencia del suelo. 
 
 La energía se puede agrupar en dos tipos principales－energía potencial y energía cinética. La energía potencial es la energía asociada con la posición, composición o condición relativa de un objeto. La energía cinética es la energía asociada con el movimiento del objeto. Por ejemplo, el agua retenida detrás de una presa posee energía potencial debido a su posición sobre el suelo. Cuando fluye hacia abajo a través de los generadores, obtiene energía cinética, que puede ponerse a trabajar para generar electricidad en una central hidroeléctrica.
 
 <h4>Energía potencial</h4>
 
 La energía potencial también se conoce como energía en reposo o energía almacenada. Los tipos comunes de energía potencial incluyen la energía potencial gravitacional almacenada en una manzana que cuelga de un árbol,  la energía potencial eléctrica almacenada en un objeto debido a la atracción o repulsión de cargas eléctricas, o la energía potencial química almacenada en los enlaces entre átomos y moléculas. Además, la energía nuclear almacenada en un núcleo atómico y la energía elástica almacenada en un resorte estirado debido a su configuración son tipos de energía potencial.
 
 Normalmente, los objetos o sistemas con energía de alto potencial tienden a ser menos estables y, por lo tanto, se mueven hacia niveles de energía más bajos para lograr estabilidad. Por ejemplo, el elemento radiactivo Uranio-235 (U235) tiene un núcleo inestable. Para ganar estabilidad, se divide en elementos más pequeños pero estables y libera la energía nuclear almacenada. Esta energía liberada puede entonces ser utilizada para generar electricidad en centrales nucleares.  
 
 <h4>Energía cinética</h4>
 
 La cantidad de energía cinética de un objeto depende de su masa y velocidad. Considere dos bolas de diferentes masas que ruedan por un plano inclinado a la misma velocidad. La bola más pesada tendrá más energía cinética. Del mismo modo, cuando dos bolas de la misma masa se desplazan por un plano inclinado a diferentes velocidades, la bola que se mueve más rápido tiene más energía cinética.  
 
 También existen diferentes formas de energía cinética, incluyendo mecánica, eléctrica, radiante, sonora, y energía térmica. La energía mecánica se asocia con el movimiento de un objeto. Cuanto más rápido se mueve un objeto, más energía mecánica tiene.  Por ejemplo, una bala disparada desde una pistola o el agua que fluye por una presa son ejemplos de energía mecánica. La energía eléctrica se atribuye al flujo de cargas eléctricas, como se observa en el caso de los relámpagos durante las tormentas eléctricas o en los circuitos y dispositivos eléctricos cotidianos. La energía radiante es la forma de energía cinética que viaja como ondas electromagnéticas y puede ser experimentada en forma de luz y calor. La luz del sol es un ejemplo de energía radiante.
 
 La energía térmica está asociada con el movimiento aleatorio de átomos y moléculas. Cuando los átomos y moléculas de un objeto se mueven o vibran rápidamente, tienen una energía cinética promedio (KE) más alta y se dice que el objeto está “caliente.” Cuando los átomos y las moléculas se mueven lentamente, tienen una KE promedio más baja y el objeto se designa como “frío”. Por lo tanto, la energía térmica se puede observar a través de los cambios de temperatura de un objeto. Suponiendo que no se produce ninguna reacción química o cambio de fase (como fusión o vaporización), el aumento de la cantidad de energía térmica en una muestra de materia hará que su temperatura aumente. De manera similar, suponiendo que no se produce ninguna reacción química o cambio de fase (como condensación o congelación), la disminución de la cantidad de energía térmica en una muestra de materia hará que su temperatura disminuya.
 
 <h4>La Ley de Conservación de la Energía</h4>
 
 La energía puede convertirse de una forma a otra, pero la energía total presente antes de un cambio siempre existe en alguna forma incluso después de un cambio. Esta observación se expresa como la Ley de Conservación de la Energía. La Ley de Conservación de la Energía establece que la energía no es creada ni destruida, aunque puede ser cambiada en forma. Así, la energía total de un sistema permanece constante. Por ejemplo, la energía química (un tipo de energía potencial) se almacena en las moléculas que componen la gasolina. Cuando se quema gasolina dentro de los cilindros del motor de un automóvil, los productos gaseosos de rápida expansión de esta reacción química generan energía mecánica (un tipo de energía cinética) cuando mueven los pistones del cilindro.
 
 Este texto es adaptado de <a href="https://openstax.org/books/chemistry-2e/pages/5-1-energy-basics">Openstax, Química 2e, Sección 5,1: Fundamentos de la Energía.</a>

¿Qué es la Energía?

El universo está compuesto de materia en diferentes formas, y todas las formas de materia contienen energía.  Las diferentes formas de energía en la Tierra se originan a partir de ...

Education

Educación

JoVE Core

Chemistry

Química

Introduction: Matter and Measurement

Introducción: La materia y la medición

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

energy forms and conservation

Energy is a property of matter that appears in many forms. On Earth, most energy starts with the Sun. Plants capture light energy from the Sun and use photosynthesis to turn it into chemical energy. That stored energy can then move through living things and materials in several ways. People get energy from plant foods, and wood or coal, which come from fossilized plants, can be burned to produce heat and electricity.

Energy is defined as the ability to do work. Work happens when a force moves an object against a resisting force. Pushing a table across a room against the floor is one example. To understand changes in matter, it helps to track how energy changes from one form to another.

Energy is often grouped into two main types: potential energy and kinetic energy. Potential energy is stored energy linked to an object’s position, composition, or condition. Kinetic energy is the energy of motion. Water held behind a dam has potential energy because of its height. When it flows downward through generators, it gains kinetic energy and can help produce electricity in a hydroelectric power plant.

Potential energy is sometimes called energy at rest. It includes gravitational potential energy, such as an apple hanging from a tree, electrical potential energy from the attraction or repulsion of charges, and chemical potential energy stored in bonds between atoms and molecules. It also includes nuclear energy in an atomic nucleus and elastic energy in a stretched spring. In general, systems with high potential energy are less stable and tend to move toward lower energy states. Uranium-235 is one example. Its unstable nucleus splits into smaller, more stable elements and releases stored nuclear energy that can be used in nuclear power plants.

The amount of kinetic energy depends on mass and speed. If two balls move at the same speed, the heavier ball has more kinetic energy. If two balls have the same mass, the faster one has more kinetic energy. Kinetic energy includes mechanical, electrical, radiant, sound, and thermal energy. Mechanical energy is tied to motion, like a bullet fired from a gun or water moving down a dam. Electrical energy comes from the flow of electric charges, such as lightning or electricity in circuits. Radiant energy travels as electromagnetic waves and includes sunlight. Thermal energy comes from the random motion of atoms and molecules, so faster motion means higher average kinetic energy and a hotter object. Slower motion means lower average kinetic energy and a colder object. If no chemical reaction or phase change happens, adding thermal energy raises temperature, and removing it lowers temperature.

Energy can change form, but it is not created or destroyed. This is the Law of Conservation of Energy. The total energy in a system stays constant even when energy is converted from one form to another. Gasoline shows this change clearly. It stores chemical energy, which is a type of potential energy. When gasoline burns in a car engine, the reaction produces gases that move the pistons and create mechanical energy, which is a type of kinetic energy.

Energy Forms and Conservation

scientific laws and theories

How Science Explains Laws and Theories

Scientific laws and scientific theories describe science in two different ways. A law is a concise verbal or mathematical statement that summarizes many experimental observations. It describes or predicts aspects of the natural world that stay the same under the same conditions. A scientific theory is different because it explains why natural events happen. It is a unifying principle that gives a well-supported and testable explanation for a broad set of observations. Strong theories are the...

the scientific method

How Scientists Test a Hypothesis

Chemistry uses the scientific method to turn observations into testable answers. Scientists begin by observing a phenomenon in the physical world and then asking a question about it. This process helps explain everyday chemistry through evidence. A question leads to a hypothesis, which is a tentative explanation for what is being observed. Scientists often use earlier research and published literature to shape that idea. A strong hypothesis must be testable, meaning it can be supported by...

physical and chemical properties of matter

physical-and-chemical-properties-of-matter

Distinguishing Physical and Chemical Changes

Matter can be identified by its properties, which are the features that help us tell one substance from another. These properties fall into two main groups: physical properties and chemical properties. Understanding the difference helps explain how matter changes. A physical property is a feature of matter that is not linked to a change in chemical composition. Examples include density, color, hardness, melting point, boiling point, and electrical conductivity. Some physical properties can be...

what is energy?

Energy is a property of matter that appears in many forms. On Earth, most energy starts with the Sun. Plants capture light energy from the Sun and use photosynthesis to turn it into chemical energy. That stored energy can then move through living things and materials in several ways. People get energy from plant foods, and wood or coal, which come from fossilized plants, can be burned to produce heat and electricity. Energy is defined as the ability to do work. Work happens when a force moves...

classifying matter by state

States of Matter and Their Properties

States of matter help describe how matter behaves in chemistry. Matter is anything that has mass and takes up space. It is found everywhere, including air, water, soil, mountains, and even our bodies. The three common states on Earth are solid, liquid, and gas. A solid has a definite shape and a definite volume. Its particles, such as atoms or molecules, are packed very closely together and held in place by strong forces, so they only vibrate slightly. This tight arrangement makes solids...

measurement: standard units

Measurement: SI Units and Conversions

Measurement gives three kinds of information: a number, a unit, and an estimate of uncertainty. The number shows size or magnitude. The unit gives a standard for comparison. The uncertainty reflects possible error in the measurement. Numbers can be written in more than one way. A value may appear in decimal form or in scientific notation, which is also called exponential notation. For example, the maximum take-off weight of a Boeing 777-200ER airliner is 298,000 kilograms, or 2.98 × 10^5 kg. <br...

classifying matter by composition

Matter: Elements, Compounds, and Mixtures

Matter can be grouped by composition into pure substances and mixtures. A pure substance has a constant composition throughout and uniform properties. For example, any sample of sucrose has the same composition and the same physical properties, such as melting point, color, and sweetness, no matter where it is isolated from. A mixture contains two or more kinds of matter in varying amounts. Its parts can be separated by physical changes, such as evaporation. The components keep their own...

measurement: derived units

SI Units, Density, and Property Types

SI units and derived units help describe physical properties in chemistry. The International System of Units, or SI system, uses agreed-upon base units for seven fundamental properties: length, mass, time, temperature, electric current, amount of substance, and luminosity. Units made by combining these base units are called SI-derived units. Speed is one example. If distance is measured in meters and time in seconds, the derived unit for speed is meters per second, or m/s. Miles per hour is...

dimensional analysis

Using Conversion Factors to Cancel Units

Dimensional analysis is a method for using conversion factors to cancel units and solve measurement problems. It is also called the factor label method. The main rule is that units must be treated the same way as the numbers attached to them. A conversion factor is a ratio of two equal quantities written in different units. For example, 1 meter is equal to 1.0936 yards. That relationship can be used to build a factor that converts one unit into the other. When a value is multiplied or divided...

uncertainty in measurement: accuracy and precision

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Measurement Error: Reading Results Correctly

Measurement error affects how scientists judge the quality of their results. Repeated measurements help show whether results are precise and accurate. A measurement is precise when repeated values are very similar. A measurement is accurate when it is very close to the true or accepted value. Precise values agree with each other, while accurate values agree with the true value. A pharmaceutical quality control chemist can use this idea to check machines that dispense 500 mL of cough syrup. The...

uncertainty in measurement: reading instruments

uncertainty-in-measurement-reading-instruments

Measurement Uncertainty and Significant Figures

Measurement uncertainty and significant figures show how carefully a value can be read from an instrument. Counting is different. If the number of objects does not change during counting, the result is exact. Defined quantities are exact too. For example, 1 foot is exactly 12 inches, 1 inch is exactly 2.54 centimeters, and 1 gram is exactly 0.001 kilograms. Most other measurements are not exact because the measuring process has limits. The result depends on the device used and on the person...

uncertainty in measurement: significant figures

uncertainty-in-measurement-significant-figures

Significant Figures and Rounding Rules

Significant figures and rounding rules help students report measurements with the right level of certainty. A measurement includes every digit that was actually measured, including the last uncertain digit. That is why a value can look simple but still carry useful information about the tool used to measure it. Zero can also be significant when it is part of a measured value. For example, if a scale reads 140 pounds to the nearest pound, the 1, 4, and 0 are all significant. Reporting...

key terms and concepts

Explore how energy moves from the Sun to plants, how potential and kinetic energy work, and why the law of conservation of energy matters.

Energy Forms and Conservation | JoVE K12

chemistry

JoVE Core Química da vida a los conceptos de química general mediante lecciones de vídeo basadas en animaciones, concisas y fáciles de entender. Además, en los vídeos de científicos en acción, se muestran experimentos de investigación clásicos y originales realizados en laboratorios de todo el mundo.

3.2.9-12.R

Life Science

matter-and-energy-in-organisms-and-ecosystems

Matter and Energy in Organisms and Ecosystems

3.1.9-12.F

Louisiana Student Standards for Science

High School

HS-PS3-3

HS-PS3-4

Life Sciences

from-molecules-to-organisms-structures-and-processes

From Molecules To Organisms: Structures And Processes

HS-LS1-7

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Study Of Matter

Classification of matter

Tennessee Academic Standards

Physics

PHYS.PS3.2

PHYS.PS3.3

CHEM1.PS3.4

Virginia  Standards of Learning

HIgh School

CH.7

CH.7.a

Arizona Science Standards

Earth and Space Science

HS.E1

HS.E1U1.12

HS.E1U1.13

HS+Phy.P4

HS+Phy.P4U1.6

HS.P4

HS.P4U3.9

Alabama Course of Study Science

9-12.PS.1.1

Matter and Its Interactions

9-12.PS.3.4.h

Earth's Place in the Universe

9-12.ESS.1.1

Next Generation Science Standards

Florida Department of Education

SC.912.E.7

SC.912.E.7.1

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

C-PS3-4

P-PS3-1

P-PS3-2

P-PS3-3

Georgia Standards of Excellence

SPS7.

Types of Energy

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Energy Basics

Chemical reactions, such as those that occur when you light a match, involve changes in energy as well as matter.

Chemical changes and their accompanying ...

Conservation of Mechanical Energy

The mechanical energy E of a system is the sum of its potential energy U and the kinetic energy K of the objects within it. What happens to this ...

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Conservation of Energy

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Conservation of Energy: Application

When solving problems using the energy conservation law, the object (system) to be studied should first be identified. Often, in applications of energy ...

Students who demonstrate understanding can create a computational model to calculate the change in the energy of one component in a system when the change in energy of the other component(s) and energy flows in and out of the system are known. Clarifying Statement: Emphasis is on explaining the meaning of mathematical expressions used in the model. Assessment Boundry: Assessment is limited to basic algebraic expressions or computations; to systems of two or three components; and to thermal energy. kinetic energy, and/or the energies in gravitational, magnetic, or electric fields.

3.2.9-12.O

Types of Potential Energy

Potential energy is also known as energy at rest or stored energy. Common types of potential energy include the gravitational potential energy stored in ...

Types of Kinetic Energy

The amount of kinetic energy of an object depends on its mass and speed. Consider two balls of different masses rolling down an inclined plane at the same ...

Kinetic Energy - I

It&#8217;s plausible to suppose that the greater the velocity of a body, the greater effect it could have on other bodies. This does not depend on the ...

Kinetic Energy - II

The kinetic energy of a particle is one-half of the product of the particle&#8217;s mass and the square of its speed. Note that just as Newton&#8217;s ...

Gravitational Potential Energy

Potential energy is not just a property of each object, but also a property of the interactions between objects in a chosen system. For each type of ...

Elastic Potential Energy

Elastic potential energy is the energy stored as a result of the deformation of an elastic object, such as the stretching of a spring. An object is ...

Energy in Simple Harmonic Motion

To determine the energy of a simple harmonic oscillator, consider all the forms of energy it can have during its simple harmonic motion. According to ...

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Problem Solving: Energy in Simple Harmonic Motion

Simple harmonic motion (SHM) is a type of periodic motion in time and position, in which an object oscillates back and forth around an equilibrium ...

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Kinetic and Potential Energy of a Wave

All forms of waves carry energy; this is directly visualized in nature. For instance, the waves of earthquakes are so intense that they can shake huge ...

Energy and Power of a Wave

The total energy associated with a wavelength is the sum of the potential energy and the kinetic energy. The average rate of energy transfer associated ...

Energy Carried By Electromagnetic Waves

Anyone who has used a microwave oven knows there is energy in electromagnetic waves. Sometimes, this energy is obvious, such as in the summer sun&#39;s ...

Students who demonstrate understanding can develop and use models to illustrate that energy at the macroscopic scale can be accounted for as a combination of energy associated with the motions of particles (objects) and energy associated with the relative positions of particles (objects). Clarifying Statement: Examples of phenomena at the macroscopic scale could include the conversion of kinetic energy to thermal energy, the energy stored due to position of an object above the earth, and the energy stored between two electrically-charged plates. Examples of models could include diagrams, drawings, descriptions, and computer simulations. Assessment Boundry: N/A

3.2.9-12.P

The universe is composed of matter in different forms, and all forms of matter contain energy. &#xA0;The different forms of energy on Earth originate from ...

Energy Transfer in Chemical Reactions

Chemical reactions require sufficient energy to cause the matter to collide with enough precision and force that old chemical bonds can be broken and new ...

Students who demonstrate understanding can design, build and refine a device that works within given constraints to convert one form of energy into another form of energy. Clarifying Statement: Emphasis is on both qualitative and quantitative evaluations of devices. Examples of devices could include Rube Goldberg devices, wind turbines, solar cells, solar ovens, and generators. Examples of constraints could include use of renewable energy forms and efficiency. Assessment Boundry: Assessment for quantitative evaluations is limited to total output for a given input. Assessment is limited to devices constructed with materials provided to students.

Students who demonstrate understanding can plan and conduct an investigation to provide evidence that the transfer of thermal energy when two components of different temperature are combined within a closed system results in a more uniform energy distribution among the components in the system (second law of thermodynamics). Clarifying Statement: Emphasis is on analyzing data from student investigations and using mathematical thinking to describe the energy changes both quantitatively and conceptually. Examples of investigations could include mixing liquids at different initial temperatures or adding objects at different temperatures to water. Assessment Boundry: Assessment is limited to investigations based on materials and tools provided to students.

force-and-potential-energy-in-one-dimension

Force and Potential Energy in One Dimension

Force can be calculated from the expression for potential energy, which is a function of position. The component of a conservative force, in a particular ...

force-and-potential-energy-in-three-dimensions

Force and Potential Energy in Three Dimensions

Consider a particle moving under the action of a conservative force that has components along each coordinate axis. Each component of force is a function ...

Energy Diagrams - I

The dynamics of a mechanical system can be easily understood by interpreting a potential energy diagram. Since energy is a scalar quantity, the ...

Energy Diagrams - II

Energy diagrams are important to understand the dynamics of a system. The topology of an energy diagram helps illustrate the equilibrium points of the ...

Students who demonstrate understanding can develop and use a model of two objects interacting through electric or magnetic fields to illustrate the forces between objects and the changes in energy of the objects due to the interaction. Clarifying Statement: Examples of models could include drawings, diagrams, and texts, such as drawings of what happens when two charges of opposite polarity are near each other. Assessment Boundry: Assessment is limited to systems containing two objects.

3.2.9-12.S

Energy Forms and Conservation

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