Law of Conservation of Energy
It states that energy can neither be created nor destroyed, but it can be transformed from one form to another.
The total energy before and after the transformation remains the same.
potential energy + kinetic energy = constant
`"mgh" + 1/2"mv"^2 = "constant"`
The sum of kinetic energy and potential energy of an object is its total mechanical energy.
We find that during the free fall of the object, the decrease in potential energy, at any point in its path, appears as an equal amount of increase in kinetic energy. (Here the effect of air resistance on the motion of the object has been ignored.) There is thus a continual transformation of gravitational potential energy into kinetic energy.
Shaalaa.com | Conservation of Energy
Illustrate the law of conservation of energy by discussing the energy changes which occur when we draw a pendulum bob to one side and allow it to oscillate. Why does the bob eventually come to rest? What happens to its energy eventually? Is it a violation of the law of conservation of energy?
Explain how, the total energy a swinging pendulum at any instant of time remains conserved. Illustrate your answer with the help of a labelled diagram.
The following data was obtained for a body of mass 1 kg dropped from a height of 5 metres :
Distance above ground
|5 m||0 m/s|
|3.2 m||6 m/s|
|0 m||10 m/s|
Show by calculations that the above data verifies the law of conservation of energy (Neglect air resistance). (g = 10 m/s2).