Hw answer:-5m/s 56:15 sir you forgot to differentiate 2t in this question. BTW session was amazing, first I was confuses to use instantaneous & average velocity in questions, but After watching your lecture, I can understand that concept. Thank you sir.
Relative means in comparison for example train speed bus ke relative mai zayda hai and also speed is relative kyuki alag alag cheezon ki speed different hoti hai.....