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?

Energy is defined as the ability to do work. Work is defined as the distance covered by an object in response to an applied force. For example, when a book is lifted from the ground and put &nbsp;on a table, work is done against the force of gravity.&nbsp;

Energy is categorized into two main types － potential and kinetic.

Potential energy is the energy associated with the position, composition, or condition of an object. It is also known as the energy at rest or the stored energy. For example &mdash; the book held above the ground&nbsp;on the table possesses potential energy due to its height. This potential energy remains stored in the book as long as it is held in&nbsp;that position.

Different forms of potential energy include gravitational potential energy, electrical potential energy, chemical potential energy, nuclear energy, and elastic energy.

Gravitational potential energy is the most apparent form of potential energy, and it depends on the relative position of the object under the influence of the gravitational field. For instance, the book held above the table has gravitational potential energy stored in it.&nbsp;

Electrical potential energy comes from the attraction or repulsion of electric charges, such as, the energy stored inside a capacitor in an electrical circuit is in the form of electric potential energy.

Chemical potential energy is the energy stored in molecules. For example, dry wood stores chemical potential energy which is released and converted into other forms of energy when the wood burns.&nbsp;

Nuclear energy comes from the atomic nucleus...and elastic energy is the energy stored in an object due to its configuration, such as a stretched slingshot.

Kinetic energy is that which is associated with the motion of an object. For instance, when the book falls from the table, its potential energy gets converted into kinetic energy due to its motion.

Kinetic energy itself also exists in different forms &mdash; namely mechanical, electrical, thermal, and radiant energies.

While mechanical energy is due to the mechanical movement of an object like a moving car, electrical energy is constituted by the flow of electric charges, as seen in lightning strikes. When kinetic energy is in the form of electromagnetic waves, such as the energy from sunlight, it becomes radiant energy.&nbsp;

Thermal energy is the kinetic energy associated with the motion of atoms and molecules in an object. &nbsp;As the atoms and molecules within an object move or vibrate quickly and collide more frequently with each other, the temperature of the object increases. The heat from a burning flame is an example of thermal energy.

The opposite happens when the vibrations or motions of these atoms and molecules slow down. The object is then said to be cold and have low thermal energy - like when water freezes.

All these different forms facilitate the flow of energy from one type to another, or from one object to another, to get the work done.

The law of conservation of energy states that energy is neither created nor destroyed &mdash;&nbsp;it only transforms from one type to another. The total energy of the system, therefore, remains conserved.&nbsp;

During archery, for example, an arrow held in a stretched bow contains elastic potential energy. When the bow is released, this potential energy gets converted into kinetic energy of the arrow, and the arrow is propelled to hit the target. Again, the total energy remains conserved.

what is energy?

The universe is composed of matter in different forms, and all forms of matter contain energy. &nbsp;The different forms of energy on Earth originate from the Sun &mdash; the ultimate energy source. Plants capture light energy from the Sun, and, via the process of photosynthesis, convert it into chemical energy. This stored energy from plants can be harnessed in many ways. For example, eating plant products as food provides energy for our body to function, and burning wood or coal (fossilized plants) generates heat and electricity. Therefore, since all changes of matter involve changes in energy, it is vital to understand how energy flows from one form to the other.&nbsp;

Energy is defined as the ability to do work. Work is done when a force applied to an object causes the object to move against an opposing force. For example, work is done when a table is pushed across a room against the resistance from the floor.&nbsp;

Energy can be grouped into two main types－potential energy and kinetic energy. Potential energy is the energy associated with the relative position, composition, or condition of an object. Kinetic energy is the energy associated with the motion of the object. For instance, water held behind a dam possesses potential energy due to its position above the ground. When it flows downward through generators, it gains kinetic energy, which can be put to work to generate electricity in a hydroelectric power plant.

<h4>Potential Energy</h4>

Potential energy is also known as energy at rest or stored energy. Common types of potential energy include the gravitational potential energy stored in an apple hanging from a tree, &nbsp;the electrical potential energy stored in an object due to the attraction or repulsion of electric charges, or the chemical potential energy stored in the bonds between atoms and molecules. Additionally, the nuclear energy stored in an atomic nucleus and the elastic energy stored in a stretched spring due to its configuration are types of potential energy.

Usually, objects or systems with high potential energy tend to be less stable, and thus move towards lower energy levels to attain stability. For instance, the radioactive element Uranium-235 (U235) has an unstable nucleus. To gain stability, it splits into smaller but stable elements and releases the stored nuclear energy. This released energy can then be used to generate electricity in nuclear power plants.&nbsp;

<h4>Kinetic Energy</h4>

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 speed. The heavier ball will have more kinetic energy. Similarly, when two balls of the same mass roll down an inclined plane at different speeds, the ball that moves faster has more kinetic energy.&nbsp;

Different forms of kinetic energy also exist, including mechanical, electrical, radiant, sound, and thermal energy. Mechanical energy is associated with the motion of an object. The faster an object moves, the more mechanical energy it has. &nbsp;For example, a bullet fired from a gun or water flowing down a dam are examples of mechanical energy. Electrical energy is attributed to the flow of electric charges, as observed in the case of lightning strikes during thunderstorms or the everyday electrical circuits and devices. Radiant energy is the form of kinetic energy that travels as electromagnetic waves and can be experienced in the form of light and heat. Sunlight is an example of radiant energy.

Thermal energy is associated with the random motion of atoms and molecules. When the atoms and molecules in an object move or vibrate quickly, they have a higher average kinetic energy (KE), and the object is said to be &ldquo;hot.&rdquo; When the atoms and molecules are moving slowly, they have lower average KE, and the object is designated as &ldquo;cold.&rdquo; Thus, thermal energy can be observed through the temperature changes of an object. Assuming that no chemical reaction or phase change (such as melting or vaporizing) occurs, increasing the amount of thermal energy in a sample of matter will cause its temperature to increase. Similarly, assuming that no chemical reaction or phase change (such as condensation or freezing) occurs, decreasing the amount of thermal energy in a sample of matter will cause its temperature to decrease.

<h4>The Law of Conservation of Energy</h4>

Energy can be converted from one form to another, but the total energy present before a change always exists in some form even after a change. This observation is expressed as the Law of Conservation of Energy. The Law of Conservation of Energy states that energy is neither created nor destroyed, although it can be changed in form. Thus, the total energy of a system remains constant. For example, chemical energy (a type of potential energy) is stored in the molecules that compose gasoline. When gasoline is combusted within the cylinders of a car&rsquo;s engine, the rapidly expanding gaseous products of this chemical reaction generate mechanical energy (a type of kinetic energy) when they move the cylinder&rsquo;s pistons.

This text is adapted from <a href="https://openstax.org/books/chemistry-2e/pages/5-1-energy-basics">Openstax, Chemistry 2e, Section 5.1: Energy Basics.</a>

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

Education

JoVE Core

Chemistry

Introduction: Matter and Measurement

KEY TERMS AND CONCEPTS

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...

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...

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...

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

uncertainty-in-measurement-accuracy-and-precision

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 Chemistry brings general chemistry concepts to life using concise and easy-to-understand animated video lessons. Plus, in the scientist-in-action videos, we demonstrate classical and original research experiments performed in today's laboratories worldwide.

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

The universe is composed of matter in different forms, and all forms of matter contain energy.&#160; The different forms of energy on Earth originate from ...

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 ...

/files/media/science-education/science-education-thumbs/14702.jpg

Conservation of Energy

The terms &#39;conserved quantity&#39;&#160;and &#39;conservation law&#39;&#160;have specific scientific meanings in physics, which differ from the ...

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 ...

/files/media/science-education/science-education-thumbs/12765.jpg

problem-solving-energy-in-simple-harmonic-motion

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 ...

/files/media/science-education/science-education-thumbs/14743.jpg

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

Description

Transcript

Tags

More videos by Standards