Potential energy function
If a force acting on an object is only a function of its position, it is said to be a conservative force and can be represented as a function of the potential energy that, in the case of one dimension, satisfies the derived condition. The integral form of this relationship is that it can be taken as a definition of potential energy.
Types of potential energy
Gravitational potential energy:
This type of potential energy is defined on the basis of the gravitational attraction of the earth or between masses of different magnitudes located close to each other. These masses can be those of the sun and orbiting planets, or those of a roller coaster when it reaches the top of the hill.
In this last example, the potential energy that the gravitational pull of the Earth accumulates in the car reaching the top is as large as possible on its planned route, and then it is transformed into kinetic energy to release the car as it falls over the rails. At this point of maximum energy accumulation, its velocity will be 0 and there will be no movement.
Elastic potential energy:
The elastic energy potential has to do with the property of the elasticity of matter, which is the tendency to recover its initial shape abruptly after being subjected to deformation forces greater than its force. This abrupt movement is what operates on the springs, which are compressed and decompressed, or gives meaning to old weapons of war, such as catapults, or bows that shoot arrows.
In this last example, the potential elastic energy reaches its maximum level as the arc is drawn by pulling the elastic fiber, slightly bending the wood, but still with a speed equal to 0. The next instant, the potential energy is returns kinetic and the arrow is thrown forward at full speed.
Chemical potential energy:
The combustion engine converts potential chemical energy into kinetic energy.
In the case of chemical potential energy, we refer to the way in which atoms and molecules are structured into chemical bonds capable of storing energy, as occurs in the body of animals with glucose, the compound from which we obtain energy. to fuel our metabolism.
The latter is given by the oxidation of the glucose molecule, whose bonds, when broken, release the potential chemical energy contained in them. The same happens, for example, with fossil fuel (hydrocarbons) in the car’s gasoline tank, before being subjected to combustion in the engine that will convert its potential chemical energy into kinetic energy to start the vehicle.
Electrostatic potential energy:
In terms of electricity, the concept of potential energy also applies, especially when it comes to electrical circuits (in which electricity is conserved) or current storage methods, which can be converted into other forms of energy, such as kinetics. , thermal or light, given the enormous versatility of electricity.
The electric potential is calculated through the energy of the electrostatic potential, which can be repulsive (if the charges are the same) or attractive (if they have different signals), giving rise to positive or negative potential energy, as the case may be.
Examples of potential energy
When we fill a balloon, we are forcing a gas to stay in a limited space. The pressure exerted by this air stretches the walls of the balloon. When we finish filling the balloon, the system stops. However, the compressed air inside the balloon has a large amount of potential energy. If a balloon explodes, this energy is converted into sound and kinetic energy.
An apple on a tree branch:
While suspended, it has potential gravitational energy, which will be available as soon as it is disconnected from the branch.
The parrot is suspended in the air thanks to the effect of the wind. If the wind stops, its potential gravitational energy will be available. The kite is generally taller than the apple on the tree branch, meaning its gravitational potential energy (weight for height) is higher. However, it falls more slowly than an apple. This is because the air exerts a force opposite to gravity, which is called “friction.” Since the barrel has a larger surface area than the apple, it suffers a greater frictional force when it falls.
The mobile phone on the roller coaster draws its potential energy as it rises to the peaks. These peaks function as unstable mechanical equilibrium points. To reach the first upper peak, the cell phone must use the power of its engine. However, once up, the rest of the trip is made thanks to potential gravitational energy, which can even cause it to climb to new peaks.
A simple pendulum is a heavy object attached to a shaft by an inextensible wire (which keeps its length constant). If we locate the heavy object two meters high and let it go, on the opposite side of the pendulum it will reach exactly two meters high. This is because its potential gravitational energy leads it to resist gravity to the same extent that it was attracted to it. Pendulums eventually stop due to the frictional force of the air, never due to the force of gravity, as this force continues to cause movement indefinitely.
Sit on a sofa:
The cushion of the sofa we sit on is compressed (deformed) by our weight. In this deformation is the potential elastic energy. If there is a feather on the pad, when we remove the weight from the pad, the elastic potential energy will be released and the feather will be expelled by this energy.
Inside a battery, there is a certain amount of potential energy that is activated only by the junction of an electrical circuit.