All You Need to Know About the Law of Conservation of Energy in Physics

Credit: Richard Bartz/Wikimedia Commons

By Andrew Bennett

What Is the Law of Conservation of Energy?

There are many different types of energy, such as kinetic, potential, mechanical, and chemical energy. Although the amount of these energies change, the total amount of energy cannot change. This rule is called the law of conservation of energy.

Law of Conservation of Energy Definition

Energy can leave or enter a system. It can transform from one form to another, such as potential energy changing to kinetic energy. However, it cannot disappear into or appear from nowhere. It may be a tough job to track it down, but that energy is somewhere!

Conservation of Energy Equation

This energy conservation equation is always true:

$K_0+U_0+W_{NC}=K+U$

This is read as "kinetic energy initial + potential energy initial + work from non-conservative forces = kinetic energy final plus potential energy final."

The most common "non-conservative forces" that would do work in most problems would be applied forces (like a person pushing or pulling on the object), friction, or air resistance. Most early physics problems will not include those forces at all, in which case, the equation would simplify to:

$K_0+U_0=K+U$

However, it might be written differently depending on the types of energy and forces involved in a particular scenario.

Conservation of Energy Videos

Want to learn more about energy conservation? For an example and a more detailed definition of the law of conservation of energy, check out the video below.

Introductory Video

In this video, you will learn more about some of the different types of energy. You will also learn how to apply this physics law to a system to make predictions about the outcome of a scenario.

AP Physics 1 Energy Videos

Ready for a more in-depth look at energy conservation? Check out this playlist for 20+ AP Physics 1 energy videos.

Subscribe for More Physics Videos

Like what you saw? Make sure you subscribe to my channel for videos about common physics equations, laws, experiments, demos, and more!

Comments

Why Do They Do That? The Physics Behind 3 Famous Animal Behaviors

By Amber Bennett Have you ever wondered about the origins of the phrase, "get your ducks in a row"? What about how the "doggy paddle" works or why squirrels are such amazing jumpers? The answers to all of these questions have one thing in common: physics. Keep reading to learn about the science behind these three famous animal behaviors. How Do Squirrels Leap from Branch to Branch? A squirrel leaps through the air. Photo Credit: caroline legg , CC BY 2.0 , via Wikimedia Commons The death-defying acrobatic maneuvers performed by squirrels look a lot like parkour tricks. But how do they know how to land tricky jumps between bendy tree branches that move with the wind? Researchers say it's a combination of learned behavior (practice makes perfect) and inherited adaptations. To see what determines how far a squirrel is willing to jump and how the leaps are timed, researchers set up an obstacle course in an artificial forest. Then, they used peanuts ...

3 Easy Science Experiments to Do with Your Kids

By Amber Bennett Strong STEM (science, technology, engineering, and math) skills set kids up to succeed both in school and later in life. Encouraging them to be interested in these subjects is easier than you might think, especially if you start when they're young. Activities that encourage children to be curious and creative will spark a love of learning. Plus, science experiments and other hands-on STEM projects are a fun way to bond with your kids. Here are three easy science experiments that preschoolers and early elementary students will enjoy. 1. Leakproof Plastic Bag A (age 5) doing the leakproof plastic bag experiment. Our preschooler loves to do any experiment that involves water. I can give her a couple of beakers, and she'll happily pour water back and forth between them, especially if I put a few drops of food coloring in each beaker so she can mix the colors. Another great activity that involves water is the leakproof plastic bag. All you need are: Large p...

How Virtual Currency Mining Is Hurting the Environment - Science in the News

Datacenters used for cryptocurrency mining use a lot of energy. By Amber Bennett Although cryptocurrencies are virtual, they are having a tangible impact on our environment. Research shows that cryptocurrencies actually are worse for the earth than other types of money. So, why is that? Simply put, it's because of the resources needed to run the supercomputers that mine Bitcoin and other virtual currencies. Energy Use The datacenters used for mining use large amounts of electricity. For example, the global Bitcoin network uses more energy than entire countries . In fact, according to the University of Cambridge Bitcoin Electricity Consumption Index , the network's power demand is the same as more than 14 million typical American homes. Most of the energy used in the datacenters comes from fossil fuels instead of renewable resources. Plus, datacenters' high energy use can destabilize the electric grid. Materials Mining Another way that cryptocurrency impacts the environme...

Bennett Science Blog

Search This Blog