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Middle school physics - NGSS
Course: Middle school physics - NGSS > Unit 3
Lesson 2: Potential energyPotential energy
Potential energy is type of stored energy that an object or system of objects may have based on their size, shape, position, or even material they are made from. Learn about what potential energy is and the different types of potential energy an object may have.
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What is the difference between electric potential energy and electric forces? Both of them have the same thing: Opposites attract, and similarities repel.(5 votes)
Hey,
You have the basic idea: opposites charges attract and similar charges repel.
However, electric potential energy is the energy needed to move a charge against an electric field. Imagine that the Earth is a positively charged ball. Now all positive ions would move away from the Earth, naturally, so the question would be how much work would be needed to move a positive ion towards the Earth.
It would be similar to thinking about gravitational potential energy but reversed, because now (in Electrical Potential Energy) energy is needed to move a positive ion toward the "ball" not away.
So, in summary, both ideas revolve around the fact of opposites charges attract and similar charges repel. But, electric potential energy develops on that basic idea and is the amount of stored energy (potential energy) when two similarly charged ions are moved closer to each other.
Hope that helps.(17 votes)
A good way of seeing it is theoretical energy or am I wrong?(7 votes)
Yes, that’s a good way of seeing it. Potential energy is a type of energy that is stored in an object due to its position relative to other objects. It is theoretical energy because it has the potential to become kinetic energy.(5 votes)
- What is potential energy(1 vote)
- When energy is stored in something(9 votes)
who is making these videos?(6 votes)
People that work at Khan Academy(1 vote)
In school I learned that there is also chemical potential energy. How does that work?(2 votes)- You are correct. Chemical potential energy is the energy stored in the chemical bonds of a substance. When the substance undergoes a chemical reaction, the bonds are broken and the energy is released. This energy can be used for various purposes, such as powering a car engine or heating a house1.
For example, gasoline contains a large amount of chemical potential energy that is released when it is burned in a controlled way in the engine of a car2.
I hope this helps. Let me know if you have any other questions.(6 votes)
What is the difference between gravitational forces and gravitational potential energy?(2 votes)
The gravitational force only depends on the mass of an object. The gravitational potential energy depends on both the mass as well as its position. Gravitational force is the pull on the object, or its weight. Gravitational potential energy is the potential to do work because of its position(5 votes)
yep your correct(2 votes)
- Are all types of energy somewhat connected to each other?(2 votes)
- Yes, all types of energy are connected to each other. For example, potential energy can be converted into kinetic energy and vice versa. When an object is dropped from a height, its potential energy is converted into kinetic energy as it falls. Similarly, when a moving object comes to a stop, its kinetic energy is converted into potential energy.
I hope this helps. Let me know if you have any other questions.(2 votes)
- how do you find potential energy?(1 vote)
that depends on what kind of potential energy your speaking of,
gravitational potential energy: imagne a bird on branch 5 feet in the air, the bird is not falling, but there is a chance for the bird to fall, and the bird would only fall because of earths gravitatinal pull, causing energy to pull the bird down.
kinetic energy: `ok, so a ball is sitting on the grass, still. a boy is about to kick it, simple.(4 votes)
Video transcript
- [Narrator] Hello, everyone. Let's talk about potential energy. Potential energy is energy
that is stored in an object, and this energy is related to the potential or the future possibility for an object to have a
different type of energy, like kinetic energy for motion, that is converted from
that potential energy. There are many kinds of potential energy, but they all arise from
an object's relation to a position, or an original shape. So while in general, there are many different
types of potential energy, there are several specific
types that are very common. So, let's talk about these. Gravitational potential energy is the potential energy
that an object with mass has due to the force of gravity
from another object with mass, like say, the Earth. And in fact, we often use
the surface of the Earth to compare an object's position with to see how much potential energy it has in the Earth's gravitational field. Gravity is an attractive force, so objects with mass want to move towards the surface of the Earth. If we move them further away, or opposite the direction
of the gravitational force, we increase their
gravitational potential energy. And the opposite is
true if it gets closer. When an object is on the surface of Earth, we typically say it has
no potential energy, but you could use any
point to be this comparison where potential energy is zero. Consider a book on a bookshelf. If the book is on this shelf, we can use this shelf as
the 0.4 potential energy. Moving it to a higher shelf would mean it has
gravitational potential energy relative to that lower shelf, or relative to the floor if we want to use that as
our comparison instead. Next, we have elastic potential energy, which is the potential energy some objects have due to
their shape being changed. These types of objects are
called elastic objects. Elastic objects are made
of materials and designed, so they have internal or inside forces that try to return them
to their original shape. One very common example
of this is a spring. When you stretch or compress a
spring, you change its shape. And the shape of the spring
causes internal forces that try to return the
spring to its original shape. Now electric potential energy, which is the potential
energy a charged object has due to the electric force
from another charged object. Opposite electric charges
are attracted to one another, and similar electric charges are repelled. So the potential energy depends on what type of charges there are, and how far apart they are. Potential energy increases when the charges move
opposite the direction of the electric force, for example, when two negative
charges get closer together. Similarly, magnetic potential energy is the potential energy
a magnetic object has due to the magnetic force
from another magnet. Magnetic force causes similar
poles to repel one another, and opposite poles to attract. And because magnets have
north and south poles, the potential energy depends not only on the position within a field, but also the magnets orientation. Again, you could increase
the potential energy by moving the magnets
opposite the direction of the magnetic force. For example, by pulling apart
a North Pole and a South Pole. All of these types of energy
are due to different forces, and are calculated differently
from different equations, which we won't cover here, but they are all potential energy. And these are just a few
of the most common types of potential energy, but there are more. In summary, potential
energy is the stored energy in an object due to its
position, its properties, and the forces acting on it. Potential energy is measured relative to some comparison
position or shape, and describes the potential
for other forms of energy, commonly kinetic energy
for motion, to exist. There are many forms of potential energy, including gravitational,
elastic, magnetic, and electric. Thanks for watching, and I hope you learned a
little bit of something.