InterviewSolution
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InterviewSolution
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Derive an expression for the kinetic energy of a body. |
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Answer» Consider a body of mass ‘m’ at rest. Let a constant force F act on the body producing an acceleration ‘a’ for a distance ‘s’. Let the velocity of the body be changed to v. In this case, initial velocity = 0 final velocity = v. Using, v2 = u2 + 2as v2 = 0 + 2as v2 = 2as s =\(\frac {v^2}{2a}\) Work done F × s = m a s = ma \(\frac {v^2}{2a}\) Work done = \(\frac {1}{2}\)mv2 By definition this work done is equal to the kinetic energy. ∴ kinetic energy of the body, Ek = \(\frac {1}{2}\)mv2. |
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