Can't a system do work without free enegy?? What excatly is this free energy in simple examples.?

Answer 1

By definition free energy is that energy which can be extracted from a system to do work. Wind or compress a spring and you can extract that energy to do work. That's free energy.

Answer 2

kinetic energy is the potential difference in a body or particle such as an electron, proton, photon, or whatever moving thing from the energy it possessed as potential energy due to mass and a constant in the famous Einsteinian Formula ...
E = (m)(c)(c) mass times a constant c squared
The higher an object is located above a surface with gravity pulling that object to the surface there is potential energy expended due to kinetic motion and a change of position from the higher point to the lower end of the object's motion at the surface below... many examples of sources of available energy stores are known
wind generators have blades that are rotated by the wind and the rotational movement of the shaft attached to a electric generator produces a source of electric current that flows into a deep cycle battery network to collect electricity for later use
inertia is the tendency for a body in motion to remain traveling in the same direction and speed so long as energy available remains the same ..If a train is moving due north at 60 mph on a straight track with nothing ahead to slow the motion of the train and the train engine remains running at constant power then the assumption would be that the train will go ahead at the same speed due north until the direction of the rails are adjusted in some other direction, or unless some unforseen happening requires the Train Engineer to slow or stop the train
consumption of a fuel or a wood log in a outdoor campfire will usually be constant burning at a rate of so many minutes for each log or each can of fuel you pour on the fire
The temperature of the fire is kept within a range
The hotter the flames the less time your logs and fuel will last
Heat is Energy and Atmospheric Pressure is a useful part of physics and in meteorology it is useful to plot Temperature and Atmospheric Pressure on graphs over time
Filling your bicycle tires with air makes riding off the road better and comfortable... The tires absorb shock which is a harmful transfer of mechanical energy from the abrupt motion changes of the bicycle against parts of your thighs and feet and legs and knees and crotch and butt and your upper torso and your hands, wrists, arms, elbows, and shoulders
All your body connections are feeling the dips and bumps along your bicycle ride off the road on trails
Wear and tear on body parts are partially caused by the transfer of mechanical shock on your body along the trail rides over many years
Sailboats use the wind and water currents and the use of a rudder to travel wherever they go
Bouyancy is something used effectively to manage the motion of submersible vehicles whether small or huge
Bouyancy of a safety vest can save the life of a boater in the water after a boating mishap
Think of any activity - you will find some need for energy
You can do nothing unless you have available energy to do it
Peter T, aka de