A body of mass 2.4 kg is subjected to a force which varies with distance as shown in figure. The body starts from rest at x=0 . Its velocity at x=9 m is

Question

A body of mass 2.4 kg is subjected to a force which varies with distance as shown in figure. The body starts from rest at x=0 . Its velocity at x=9 m is <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/5b6673da423070ab7ab9f0a2c9bb01e1-.png" /> (A) 5 √3 m / s (B) 20 √3 m / s (C) 10 m / s (D) 40 m / s

Tardigrade Admin · Accepted Answer

Work done in a moving body is get converted into kinetic energy.

∴ \int F d x = \frac{1}{2} m (v^{2} - 0^{2})

\Rightarrow \frac{1}{2} (9 + 3) (20) = \frac{1}{2} (2.4) v^{2}

\Rightarrow v = 10 m / s

Q. A body of mass $2.4 k g$ is subjected to a force which varies with distance as shown in figure. The body starts from rest at $x = 0.$ Its velocity at $x = 9 m$ is

$53 m / s$

$203 m / s$

$10 m / s$

$40 m / s$

Work done in a moving body is get converted into kinetic energy.

$∴ \int F d x = \frac{1}{2} m (v^{2} - 0^{2})$
$\Rightarrow \frac{1}{2} (9 + 3) (20) = \frac{1}{2} (2.4) v^{2}$
$\Rightarrow v = 10 m / s$

Q. A body of mass 2.4kg is subjected to a force which varies with distance as shown in figure. The body starts from rest at x=0. Its velocity at x=9m is

53​m/s

203​m/s

10m/s

40m/s