Question

Principle of Conservation Energy is always being applied to solve engineering mechanic analysis. Explain what is Principle of Conservation Energy and when it is suitable to use this principle. Use appropriate real life application in your discussion.

Answer 1

in its fundamental meaning priciple of conservation energy is energy can not be created or destroyed. We can only transform it from one form to another form. In other words if a system is isolated from its surroundings, its total energy will remain constant.

i am giving few examples for the law of conservation energy in real life

In a torch

chemical energy of batteries -------> electrical energy,------------> light and heat energy.

Hydroelectric power plants

waterfalls on the turbine------> rotates the turbines and generates electricity.

potential energy of water --------------> kinetic energy of the turbine ---------------> electrical energy.

In a loudspeaker

electrical energy -------------> sound energy.

In a microphone

sound energy ----------------> electrical energy.

fuel burn

chemical energy-----------------> heat and light energy.

the important thing is conservation energy is only applicable in isolated system. Let me tell an example. Suppose a ball is rolling on a rough floor. energy conservation principle can be applied on ball? the answer is a BIG No. here the ball is not isolated system. It has interaction on the surface.more than interaction floor is doing friction work on ball. So in this case we will take both floor and ball into a single system. Then it will become a isolated system and energy conservation can be applied.this is the technique.

Real life example: 8 ball pool

When we hit cue ball against stationary balls, cue ball has energy. cue ball hits 8 balls and transfer energy. Then the eight balls start moving.  The cue ball will lose part of its energy because the energy is transferred to the eight balls, so the cue ball will get slow.

If you need more examples feel free to comment. I will reply ASAP. If you find my anser useful pleae give me a upvote. It will be very helpful for beginners like me