KEAM 2018 Physics and Chemistry Paper

(e) Two point are situated in a pipe and their height from ground is zero (h=0).
∵ According Bernoulli's theorem,
p+ρgh+‌

1

2

ρv2=‌ constant ‌
At a point pressure of water is p and speed of flow is v
therefore, p+‌

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2

ρv2=c.....(i)
At another point speed of flow is 2v therefore,
p1+‌

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2

ρ(2η)2=c....(ii)
To find pressure p1 at another point, equating the equation (i) and (ii)
⇒‌‌p+‌

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2

ρv2=p1+‌

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2

ρ(4v2)
⇒‌‌p1=p−‌

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2

ρv2