First slide

Numericals based on work energy theorem

Question

A particle of mass 0. 1 kg is subjected to a force which varies with distance as shown in the figure. If it starts its journey from rest at x = 0, its velocity at x = 12 m is

Moderate

A

0 m/s
B

$20 \sqrt{2} m / s$
C

$20 \sqrt{3} m / s$
D

40 m/s

Solution

Area between curve and displacement axis
$= \frac{1}{2} \times (12 + 4) \times 10 = 80 J$
In this time the body acquires kinetic energy= $\frac{1}{2} {mv}^{2}$ by the law of conservation of energy
$\frac{1}{2} {mv}^{2} = 80 J$
$\Rightarrow \frac{1}{2} \times 0.1 \times v^{2} = 80$
$\Rightarrow v^{2} = 1600$
$\Rightarrow v = 40 m / s$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App