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What do you mean by Kinetic energy ? Derive an expression for the Kinetic energy of an object of mass ‘m’ moving with velocity ‘v’ |
| Answer» ENERGY is the energy possessed by an object by virtue of its motion.K.E=1/2 mV²Derivation:Let us consider an object of m which is at rest lying on a table.Let A force F acts on the object which moves the object through a distance S.The workdone=FxSW=FnetXS-------(1)Let the workdone on the object causes a change in its velocity from u to V and let a be the acceleration.From THIRD equation of motion:V²-u²=2ass=V²-u²/2a----------(2)By Newton's Second law:F=ma------(3)From equation (1), (2) and (3)W=ma*(V²-u²/2a)\=(1/2)m(V²-u²)As we assumed object at rest, u=0W=(1/2)mV²we KNOW that the kinetic energy of a body moving with CERTAIN velocity is equal to workdone on the object to acquire that velocity from rest.∴K.E=1/2 mV² | |