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

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

Start Free Mock LoginAlready registered? Login here

Physics - W.E.P. Question with Solution | TestHub

PhysicsW.E.P.MiscellaneousMedium2 minQB

PhysicsMediumsingle choice

A body of mass $(5 \pm 0.5) kg$ is moving with a velocity of $(20 \pm 0.4) m s^{- 1} .$ Its kinetic energy will be

Options:

Answer:

Solution:

The kinetic energy is given by,
$K = \frac{1}{2} m v^{2}$
Differentiating the above equation,
$d K = \frac{1}{2} (v^{2} d m + 2 m v d v)$
Dividing by $K$ ,
$\Rightarrow \frac{d K}{K} = \frac{d m}{m} + \frac{2 d v}{v}$
$\Rightarrow \frac{d K}{1000} = \frac{0.5}{5} + \frac{2 \times 0.4}{20}$
$\Rightarrow d K = 100 + 40 = 140$
$\Rightarrow K E = (1000 \pm 140) J$

Stream:JEESubject:PhysicsTopic:W.E.P.Subtopic:Miscellaneous

⏱ 2mℹ️ Source: QB

Doubts & Discussion

Loading discussions...