Properties Of Matter Ques 8
- If the piston is pushed at a speed of $5 \mathrm{mms}^{-1}$, the air comes out of the nozzle with a speed of
(a) $0.1 \mathrm{~ms}^{-1}$
(b) $1 \mathrm{~ms}^{-1}$
(c) $2 \mathrm{~ms}^{-1}$
(d) $8 \mathrm{~ms}^{-1}$
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Answer:
Correct Answer: 8.( c )
Solution:
- From continuity equation,
$ A_1 v_1=A_2 v_2 $
Here, $ \quad A_1=400 A_2$
because $ \quad r_1=20 r_2$ and $A=\pi r^2$
$\begin{aligned} \therefore \quad v_2 & =\frac{A_1}{A_2}\left(v_1\right)=400 v_1 \\ & =400(5) \mathrm{mm} / \mathrm{s}=2000 \mathrm{~mm} / \mathrm{s}=2 \mathrm{~m} / \mathrm{s}\end{aligned}$
BETA
