Difference Between Potential Energy (PE) And Kinetic Energy (KE)

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Energy refers to the ability of an object or system to perform work. Energy exists in many different forms including mechanical, thermal, chemical, nuclear and others. All forms of energy are either kinetic or potential. The energy associated with position is referred to as potential energy (PE) whereas the energy associated with motion is referred to as Kinetic Energy (KE).

What Is Kinetic Energy (KE)?

Kinetic energy is the energy a body or a system possesses due to its motion. The faster an object is moving, the more kinetic energy it has. The kinetic energy of an object is calculated based on two factors, which include Velocity ( the speed the object is moving in a particular direction) and Mass (how much matter is in the object -this is usually measured by the weight of the object).

Any object in motion is using kinetic energy for example, a person walking, a thrown baseball, a crumb falling from a table and a charged particle in an electric field. There are many forms of kinetic energy and they include:

  • Vibrational- The energy due to vibrational motion.
  • Rotational-The energy due to rotational motion.
  • Translational- The energy due to motion from one location to another.

Kinetic energy is a scalar quantity, it does not have a direction unlike velocity, acceleration, force and momentum, the kinetic energy of an object is completely described by magnitude alone. Just like work and potential energy, the standard metric unit of measurement for kinetic energy is the Joules, named after James Prescott Joule, the physicist responsible for creating the formulas that make sense of energy transference.

The kinetic energy (KE) of an object is represented by the equation KE=0.5MV2   .Where M=mass of the object and V= speed of the object.

From this equation we can make the inference that Kinetic energy of an object is directly proportional to the square of its speed. What this simply means is that if speed of an object is increased twofold, the kinetic energy consequently increases by a factor of four.

What You Need To Know About Kinetic Energy

  • Kinetic energy is the energy possessed by a system or an object with respect to the motion of the body or of the particles in the system.
  • The factors that influence the magnitude of kinetic energy include speed/velocity and mass.
  • Kinetic energy of an object is relative to other moving and stationary objects in its immediate environment.
  • Kinetic energy can be classified into types, depending on the type of objects: Translational kinetic energy, Vibrational Kinetic Energy and Rotational kinetic energy.
  • The SI unit of kinetic energy is Joule (J).
  • The measurement of kinetic energy in an object is calculated based on the object’s mass and velocity.
  • The kinetic energy equation is KE=0.5 mv^2 where m=mass and v=velocity/speed.
  • Kinetic energy can be transferred from one object to another as is the case with what happens during collisions.

What Is Potential Energy (PE)?

Potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge or other factors. According to the law of conservation of energy, energy can neither be created nor destroyed. However, energy can be altered from one form to another. In this regard, Potential energy may be converted into energy of motions (kinetic energy) and in turn to other forms such as electric energy. The two main types of potential energy include Gravitational potential energy and Elastic potential energy.

Gravitational potential energy is the energy is an object that is held in a vertical position, due to the force of gravity of gravity working to pull it down whereas Elastic potential energy is energy stored in objects that can be stretched or compressed such as trampolines, rubber bands and bungee cords.

Other Types Of Potential Energy

  • Electric potential field (energy due to the object’s electric charge).
  • Nuclear potential energy (energy of the particles inside an atom.
  • Chemical potential energy (energy stored in a substance due to their chemical bonds).

Potential Energy And Work

The potential energy is equal to the amount of work done to get an object into its position. For example, if you were to lift a box off the floor and place it on a table. The potential energy of the box on the table will equal the amount of work it took to move the box from the floor to the table.

Potential Energy Equation

The potential energy (PE) of an object can be represented by the equation PE= mgh, where m represents the mass of the object, h represents the height of the object and g represents the gravitational field strength (9.8 N/kg on Earth)-sometimes referred to as the acceleration due to gravity.

From the equation we can also make the inference that there is a direct relationship between potential energy and the mass of an object, the bigger the mass of an object, the greater its potential energy. More so, potential energy of an object is directly proportional to the height of the object, the higher that an objected is elevated, the greater the gravitation potential energy.

What You Need To Know About Potential

  • Potential energy is the energy stored in an object or system because of its position or arrangement of parts.
  • The factors that influence the magnitude of potential energy include Height or distance and mass.
  • Potential energy is not relative to the environment of an object.
  • Potential energy is classified depending on the applicable restoring force. Types of potential energy include: Gravitational potential energy, Elastic potential energy, chemical potential energy, Electrical potential energy and Nuclear potential energy.
  • The SI unit of potential energy is Joule (J).
  • The measurement of potential energy in an object is calculated based on the object’s mass and its height or distance.
  • The potential energy equation is PE=mgh, where m=mass, g= acceleration due to gravity and h=height.
  • Potential energy cannot be transferred from one object to another.

Also Read: Difference Between Speed And Velocity

Difference Between Kinetic Energy And Potential Energy In Tabular Form

BASIS OF COMPARISON KINETIC ENERGY POTENTIAL ENERGY
Description Kinetic energy is the energy possessed by a system or an object with respect to the motion of the body or of the particles in the system.   Potential energy is the energy stored in an object or system because of its position or arrangement of parts.  
Factors Affecting The factors that influence the magnitude of kinetic energy include speed/velocity and mass.   The factors that influence the magnitude of potential energy include Height or distance and mass.  
Effects On the Objects In Immediate Environment Kinetic energy of an object is relative to other moving and stationary objects in its immediate environment.   Potential energy is not relative to the environment of an object.  
Types Kinetic energy can be classified into types, depending on the type of objects: Translational kinetic energy, Vibrational Kinetic Energy and Rotational kinetic energy.   Potential energy is classified depending on the applicable restoring force. Types of potential energy include: Gravitational potential energy, Elastic potential energy, chemical potential energy, Electrical potential energy and Nuclear potential energy.  
S.I Unit The SI unit of kinetic energy is Joule (J).   The SI unit of potential energy is Joule (J).  
Measurement The measurement of kinetic energy in an object is calculated based on the object’s mass and velocity.   The measurement of potential energy in an object is calculated based on the object’s mass and its height or distance.  
Equation The kinetic energy equation is KE=0.5 mv^2 where m=mass and v=velocity/speed.   The potential energy equation is PE=mgh, where m=mass, g= acceleration due to gravity and h=height.  
Transferability Kinetic energy can be transferred from one object to another as is the case with what happens during collisions.   Potential energy cannot be transferred from one object to another.