Question

The velocity-time graph of a particle of mass $10 \, kg$ is shown in the figure. The net work done on the particle in the first two seconds of the motion is

• A. $-9300 \, \text{J}$
• B. $12000 \, \text{J}$
• C. $-4500 \, \text{J}$
• D. $-12000 \, \text{J}$

Answer 1

Answer: (C)

$v=-5t+50$
$v_{a t \, t = 2}=40$
$\Delta K . E .=W . D .=\frac{1}{2}\left(40^2-50^2\right) \times 10$
$=-4500$ J