A body of mass ( 5 ± 0 . 5 ) kg is moving with a velocity of ( 20 ± 0 . 4 ) m s - 1 . Its kinetic energy will be

Step-by-step solution

The kinetic energy is given by, K = 1 2 m v 2 Differentiating the above equation, d K = 1 2 ( v 2 d m + 2 m v d v ) Dividing by K , ⇒ d K K = d m m + 2 d v v ⇒ d K 1000 = 0 . 5 5 + 2 × 0 . 4 20 ⇒ d K = 100 + 40 = 140 ⇒ K E = ( 1000 ± 140 ) J