Conservation of Energy
Conservation of Energy
Fundamentals
- The law of conservation of energy states that the total energy of a closed system is constant.
- It can be inferred that energy can neither be created nor destroyed, but it can be converted from one form to another.
- The sum of kinetic and potential energy in the system is always the same, representing the mechanical energy of an object.
Kinetic Energy and Work
- The kinetic energy of an object is the energy it possesses due to its motion.
- Described mathematically, kinetic energy (K.E) = 1/2 mv^2 where m is the mass of the object and v is its speed.
- The work done by forces, excluding the force of gravity, is equal to the change in kinetic energy of an object. This is the basis of work-energy theorem.
- Physically, work done on an object transfers energy to the object.
Potential Energy
- The potential energy of an object is the energy it possesses due to its position relative to other objects.
- Potential energy usually refers to energy that an object has because of its position in a force field, such as gravitational potential energy, or due to its configuration, like elastic potential energy.
- Gravitational potential energy is given by P.E = mgh where m is the mass of the object, g is acceleration due to gravity, and h is height above the ground.
Energy Transformations
- Due to the law of conservation of energy, energy may be converted between different forms.
- For example, an object in free fall will convert potential energy into kinetic energy as it falls towards the Earth.
- In an ideal, frictionless system, the sum of the kinetic and potential energies will remain constant, signifying conservation of mechanical energy.
Power
- Power is the rate at which energy is transferred, or the amount of energy per unit time.
- The unit of power is Joule per second (J/s), which is also known as a Watt (W).
- The power resulting from force F moving an object at velocity v is given by P=Fv.
Remember, understanding the principles of energy conservation and how to apply them in problem-solving scenarios is crucial for mastering this topic.