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Illustrate the energy changes which occur when a stone of mass m is dropped freely fr a hwight h |
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Answer» n :-Illustrate the energy changes which occur when a stone of mass m is dropped freely fall from HEIGHT h______________________Formulas :Potential energy U = mghKinetic energy K = 1/2 mv²Total energy = K + UAt AU = mghK = 0 since v = 0Total energy = K + U = mgh + 0 = mghAt BU = m g hh = h - xU = mg ( h - X )K = 1/2 m v²By LAWS of motion:v² = 2 gh= > v²= 2 gxK = mgxK + U = mg( h - x ) + mgx = mgh - mgx + mgx = mghAt CK = 1/2 m v² = 1/2 m × 2 gh [ v² = 2 gh ] = mghU = 0 since h = 0Hence K + U = mgh + 0 = mghObservations :In all cases ,K + U = mghThere fore the total mechanical energy remains constant.This verifies the Law of Conservation of Energy.__________________________________________ |
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