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## Homework Statement

The density of the liquid flowing through a horizontal pipe is 1600 kg/m3. The speed of the fluid at point A is 4 m/s while at point B it is 8.0 m/s. What is the difference in pressure, PB - PA, between points B and A?

a. -1.9 x 10^3Pa

b. -3.8 x 10^4Pa

c. +4.5 x 10^4Pa

d. +5.0 x 10^4Pa

*e. -7.7 x 10^4Pa

## Homework Equations

Pa+1/2*ρ*va

^{2}=Pb+1/2*ρ*vb

^{2}

## The Attempt at a Solution

Pb-Pa=1/2*ρ*va

^{2}-1/2*ρ*vb

^{2}

Pb-Pa=1/2*ρ*(va

^{2}-vb

^{2})

Pb-Pa=1/2*1600kg/m

^{3}*(4m/s

^{2}-8m/s

^{2})

Pb-Pa=-3.84x10

^{4}Pa

and the answer key says its -7.7 x 10^4Pa

what did I do wrong? :s