Question

Velocity-time graph of a particle moving in a straight line is as shown in figure. Mass of the particle is $2kg$. Work done by all the forces acting on the particle in time interval between $t=0$ to $t=10$ is

• A. $300J$
• B. $-300J$
• C. $400J$
• D. $-400J$

Answer 1

The correct option is A $300J$

By work energy theorem we have Work done by all forces = Change in K.E. Here at $at=Os$ Velocity (v)= 10m/s and at $t=10s$ velocity (v)= -20m/s

So, work done $\left(w\right)=\frac{1}{2}m(v{{}_2}^2-V{{}_1}^2)$

$\Rightarrow W=\frac{1}{2}\times 2(400-100)=300J$