Table of Contents
Introduction:
The capacity which is required to complete the work is called energy. We are already aware of some kinds of energy such as mechanical energy, potential energy, chemical energy, kinetic energy, thermal energy, solar energy, and much more. Let us discuss briefly about the conservation of mechanical energy in this article.
The sum of the total kinetic energy and the total potential energy in an object that is used to complete a particular work is called mechanical energy. We can also say that the mechanical describes the energy of an object due to its motion or position, or both.
At present many technological devices are responsible to convert mechanical energy into other forms of energy or vice versa. Some of the conversion is mentioned below: Electrical energy is converted into mechanical energy with the help of an electric motor. The mechanical energy is converted into electrical energy with the help of the generator. The mechanical energy of water in a storage dam is converted into electrical energy with the help of a hydroelectric power plant. The heat energy of steam is converted into mechanical energy with the help of a steam engine. The kinetic energy of a stream of gas or liquid is converted into mechanical energy with the help of a turbine.
| S.NO | CONTENT |
| 1 | INTRODUCTION |
| 2 | BRIEF OUTLINE |
| 3 | IMPORTANT CONCEPTS AND LAW |
| 4 | FAQ’S |
A brief outline of the topic:
Kinetic Energy: Kinetic energy is the ability of an object to do work by the virtue of its motion. For example, the kinetic energy of wind has the capacity to rotate the blades of a windmill and hence to produce electricity. The kinetic energy is expressed as,
K=1 ⁄ 2 m v 2
Where,
K = the kinetic energy of the object in joules (J)
m = the mass of the object in the kilograms
v = the velocity of the object
Potential energy: Potential energy is the ability of an object to do work with the help of the virtue of its position. For example, a compressed spring can do work when it is released. In this article, we will focus on discussing the potential energy of an object with the help of the virtue of its position with respect to the earth’s gravity.
Mathematically the potential energy can be expressed as follows:
V=m g h
Where,
V= the potential energy of the object in joules (J)
m = the mass of the object in the kilograms
g = the gravitational constant of the earth= 9.8 m/s²
h = the height of the object from earth’s surface.
Now as we know that the acceleration of an object will change under the influence of earth’s gravitational force according to its distance from the earth’s center of gravity.
A brief note of important concepts and laws:
The conservation of mechanical energy is defined as the sum of the total kinetic energy and total potential energy of an object. According to the conservation of energy’s law, energy cannot be created and cannot be destroyed. The conservative force is dependent on the position of the object. If a force is conservative it is possible to assign a numerical value for the potential at any point. On the contrary, when an object moves from one location to another the force changes the potential energy of the object by an amount that is not dependent on the path taken and contributes to the mechanical energy and to the overall conservation of energy. Defining a scalar potential is not possible when the force is not conservative since taking different paths would lead to conflict in the potential differences between the start and endpoints.
The conservative force can be defined as a force that is responsible for conserving mechanical energy. If there is a particle that starts at point A with a force F acting on it. Then the particle is moving around to the other forces and hence ends up at point A again. Since the particle may still move but at that instant when it passes point A again it has already traveled a closed path. If the net work done by force F at this point is 0, then F cleared the closed path test. Any forces which pass the closed path test for all possible closed paths are classified as the conservative force.
The example of conservative forces is as follows:
- The gravitational force
- The spring force
- The magnetic force
- The electric force
Also read: Momentum conservation
FAQs (Frequently Asked Questions):
Que 1: Note down the principle of the conservation of mechanical energy.
Ans: The total mechanical energy of a system is conserved, that is the energy can neither be created nor be destroyed and it can only be internally converted from one form to another form if the forces doing work on the system are conservative in nature.
Que 2: Define the mechanical energy of the system.
Ans: The mechanical energy of the system is defined as the overall kinetic energy with the overall potential energy.
Que 3: Whether the kinetic energy is conserved in the elastic collisions?
Ans: Yes, the kinetic energy is conserved in the elastic collisions.
Que 4: Name the device which converts electrical energy into mechanical energy.
Ans: The electric motor is a device that is responsible for converting electrical energy into mechanical energy.
Que 5: Give an example where heat energy is converted into mechanical energy?
Ans: The heat energy is converted into mechanical energy in the heat engine.
