This video defines and describes kinetic and potential energy. You’ll learn how different types of energy can be classified as potential and kinetic. You’ll also find out how kinetic and potential energy are transformed.
Kinetic Energy to Potential Energy: Relationship in Different Energy Types
Energy gets things done. Energy warms the surface of our planet and blows the wind through our hair. Energy contracts muscles and transmits signals within our brain.
Energy illuminates the lights in our homes and moves cars down the road. Energy is usually defined as the ability to do work. Scientists have learned how to change energy from one form into another to make our lives more comfortable. Energy exists in different forms, such as heat, motion, light, chemical, and sound. While there are different forms of energy, all the different forms can be put into two categories. One category would be kinetic energy. That’s energy of motion.
The other category is potential energy. That’s energy stored in an object due to its position.
What Is Kinetic Energy?
Let’s first explore kinetic energy.
Kinetic energy of an object is the energy it contains due to movement. If an object is at rest, it doesn’t have kinetic energy. If it’s moving, then it has kinetic energy. It’s pretty simple!The amount of kinetic energy of an object is dependent upon two variables, one being the mass of the object, the other being the speed or the velocity of the object.
Let’s look at an equation that will help us calculate kinetic energy and understand the relationship of these variables. Here it is:Kinetic Energy = ; mass x velocity^2Therefore, kinetic energy is directly proportional to both the mass of the object and the square of its speed. This is important because small changes in speed will result in larger changes in kinetic energy. For example, if a car moves twice as fast as another, it will contain four times as much kinetic energy.
That is assuming that both cars have the same mass – or even if you talk about the same car and it moves twice as fast, it will also have four times as much kinetic energy.
What Is Potential Energy?
Now that we have explored kinetic energy, let’s now take a look at potential energy. Potential energy is stored in an object when work is done on that object. Work is done when a force moves an object some distance to a new position.
In other words, potential energy is stored in a system when something is moved from its natural resting state.Let’s look at an example of potential energy. A mouse trap contains potential energy when the lever is forced into its set position. Within the mouse trap, the potential energy is stored specifically within the spring. When the trap is tripped, the potential energy is released from the spring when the trap resumes its original shape and then perhaps catches a mouse.
Potential energy can be stored in other devices as well, such as tires on your car, the shock absorbers on your car, and even wrecking balls that are used to tear down buildings. Metal beams that are used to construct buildings also contain potential energy.At a much smaller level, potential energy is stored in chemicals. This chemical potential energy is related to the arrangement of the chemicals. The arrangement may be a result of bonds that hold an individual chemical together, or the arrangement could be the arrangement of different chemicals that are existing together within a system. Let’s look at a couple of examples. Gasoline is a chemical.
That’s obviously what we use to run our automobiles. When gasoline is burned, these bonds within the gasoline are broken, and that releases potential energy. Likewise, our bodies break down food chemicals to release energy.
What Is The Relationship Between Kinetic and Potential Energy?
Now let’s explore the relationship between kinetic and potential energy. It’s difficult to discuss kinetic or potential energy alone because they’re so tightly related and even dependent upon each other.
In fact, the only way any kinetic energy will exist is if it is released from a formerly stored energy, which is potential energy. Likewise, kinetic energy is needed in order to store potential energy in any system. For example, people use potential energy in food to contract muscles that are needed to ride a bike. In this example, the potential energy from food is converted into kinetic energy, the energy of motion of the bicycle. The kinetic energy of biking can then be converted into other forms.
If the person rides the bike to the top of a hill, the kinetic energy of motion is then converted into potential energy stored in the bike at the top of the hill. The potential energy stored in the bike at the top of the hill can be used to roll the bike down the hill.
In review, energy is the capacity to do work, and work is accomplished when a force moves an object. Energy exists in different forms, all of which can be classified as either potential energy or kinetic energy. Potential energy is energy stored in an object due to its position or arrangement. Kinetic energy is energy of an object due to its movement – its motion.
All types of energy can be transformed into other types of energy. This is true for potential and kinetic energy as well. Potential energy can be converted into kinetic energy, and kinetic energy can be converted into potential energy.
After watching this lesson, you should be able to:
- Define and describe potential and kinetic energy
- Explain how energy can be transformed into other types of energy