InterviewSolution
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InterviewSolution
| 1. |
Define kinetic energy.obtain and express for the kinetic energy of an object |
| Answer» Kinetic energy of an object\xa0is the\xa0energy\xa0that it possesses due to its motion. It is\xa0defined\xa0as the work needed to accelerate a body of a given mass from rest to its stated velocity.\xa0Derivation:\xa0Let 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=F×SW=Fnet\u200b×S-------(1)Let the work done 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,\xa0u=0W=(1/2)mV2we know that the kinetic energy of a body moving with a certain velocity is equal to work done on the object to acquire that velocity from rest.∴K.E=1/2mV2 | |