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grog
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Homework Statement
The alaskan pipeline has a capacity of 2.37*105m3/day of oil per day. Along most of the pipeline the radius is 60 cm. Find the pressure at a point where the pipe has a 35 cm radius. Take the pressure in the section with radius 60 cm to be 160 kPa and the density of oil to be 800kg/m3. Answer in units of kPA
Homework Equations
.5 * rho * v12+ rho * g * y + p1 = .5 * rho * v22 + rho * g* y + p2
since y = 0, we end up with:
.5 * rho * v12+ p1 = .5 * rho * v22 + p2
v2 = v1 ( A1 / A2)
The Attempt at a Solution
v1 = 2.37x10^5 m^3/day = 2.743055556 m^3/sec
A1 = 60^2*pi = 11309.73355 cm^2
A2 = 35^2 * pi = 3848.451001 cm^2
v2 = v1 * (A1/A2)
p1-p2 (difference in pressure) = (.5)(rho)(v2^2) - (.5)(rho)(v1^2)
substitute:
= (.5)(rho) ((v1*A1/A2)^2) - (.5)(rho)(v1^2)
= (.5)(rho)(v1^2) [(a1/a2)^2 - 1]
plugging in:
= (0.5)(800)(2.743055556)^2 (7.636401493) = 22983.59459 Pa = p1-p2
since we're given p1 = 160 kPa, converting the difference in pressure to kPa and subtracting yields
22.98359459 = 160 - p2
p2 = 137.0164054 kPa
However, this is an in correct answer. Does anyone see where I'm making my mistake?