Question

State the principle of conservation of energy.

Answer 1

Hint: Define kinetic energy and the potential energy of a particle. Understand the general meaning or the physical meaning of the conservation laws. Conservation laws tell us that certain physical property or quantities in an isolated system remains constant or does not change over time.

Complete step by step answer:
Law of conservation of energy states that we cannot create or destroy any form of energy. We can only convert the energy from one dorm to another.
Law of conservation tells us that the total energy of an isolated system will remain constant over time. It may just change its form from one type of energy to another type.
Kinetic energy can be defined as the work done by an object in terms of motion. It is a scalar quantity. Kinetic energy of an object can be given as,
$\text{kinetic energy }=\dfrac{1}{2}m{{v}^{2}}$
Potential energy of an object can be defined as the energy stored in the object due to its relative position with respect to a reference point.
If we consider gravitation potential, at the surface of the earth the potential energy of the object will be 0 and for an object at a height h the potential energy will be $mgh$.
Law of conservation of energy can be given as,
$\text{total energy = kinetic energy + potential energy }\to \text{ remains constant}$
Or,
$\text{initial kinetic energy + initial potential energy = final kinetic energy + final potential energy}$

Additional information: Conservation laws state the certain physical quantity remains constant over time. For law conservation of linear momentum, total linear momentum of the system is conserved; for law conservation of angular momentum, total angular momentum of the system is conserved and for law of conservation of energy, the total energy of the system will be conserved.

Note: conservation laws can be used to make predictions of motion of particle or system of particle. If we know the initial properties of a system, we can make predictions of the final properties based on the conservation law. Nature does not seem to violate the conservation laws. These are fundamental to nature.