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Illustrate the law of conservation of energy by discussing the... - Science
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?
Illustration:
Extreme Position: When the bob is pulled to one side, it has maximum Potential Energy (P.E.) and zero Kinetic Energy (K.E.).
Downward Motion: As it swings down, P.E. decreases and converts into K.E.
Mean Position: At the bottom, P.E. is minimum and K.E. is maximum.
Upward Motion: As it swings up to the other side, K.E. converts back into P.E.
The total energy (P.E. + K.E.) remains constant throughout.
Why it stops:
The bob eventually comes to rest due to air resistance and friction at the support.
What happens to the energy:
The mechanical energy is dissipated as heat energy into the surrounding air and the support mechanism.
Violation of Law:
No, it is not a violation. The energy is not lost but transformed into other forms (heat), keeping the total energy of the system and surroundings constant.
