Tathagata Haldar (anonymous) doubts changed status

sir, in your video lecture you have shown the derivation of the formula of Kinetic Energy (K.E=1/2 mv2), but in your video lecture sometimes it is written capital v and sometimes small v, sir I am very confused so sir please can you redo the derivation of the formula of Kinetic Energy (K.E=1/2 mv2).