Question
A human is moving on a plane surface with a box in his hand whose mass is 2 kg . If he walks with an acceleration of $0.5 m / s ^2$ to distance 40 m then what will be the work done by the man on the box during the motion?
✓
Answer
Given,
$\begin{aligned}
m & =2 kg \\
a & =0.5 m / s^2 \\
s & =40 m
\end{aligned}$
Here force and displacement are in same direction, then
$\therefore \quad \theta=0^{\circ}$
$\begin{aligned}work ( W ) & =\text { mas } \cos \theta \\ & =2 \times 0.5 \times 40 \cos 0^{\circ} \\ & =2 \times 0.5 \times 40 \quad \therefore \cos 0=1 \\ W & =40 J\end{aligned}$
$\begin{aligned}
m & =2 kg \\
a & =0.5 m / s^2 \\
s & =40 m
\end{aligned}$
Here force and displacement are in same direction, then
$\therefore \quad \theta=0^{\circ}$
$\begin{aligned}work ( W ) & =\text { mas } \cos \theta \\ & =2 \times 0.5 \times 40 \cos 0^{\circ} \\ & =2 \times 0.5 \times 40 \quad \therefore \cos 0=1 \\ W & =40 J\end{aligned}$
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