Work Power and Energy 3 Question 9
9. A body of mass $2 kg$ is being dragged with a uniform velocity of $2 m / s$ on a rough horizontal plane. The coefficient of friction between the body and the surface is $0.20, J=4.2 J / cal$ and $g=9.8 m / s^{2}$. Calculate the amount of heat generated in $5 s$.
$(1980,5 M)$
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Answer:
Correct Answer: 9. $9.33 cal$
Solution:
- $s=v t=2 \times 5=10 m$
$Q=$ work done against friction
$$ \begin{aligned} & =\mu m g s=0.2 \times 2 \times 9.8 \times 10 \\ & =39.2 J=9.33 cal \end{aligned} $$
