Conceptual question: Atmospheric pressure

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johnj7
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Homework Statement


A stream of water flows vertically downward at a speed of v1 = 2.0 m/s from a faucet of cross sectional area A = 0.5 cm^2 to the bottom of a sink a distance h = 20 cm below.

Homework Equations


Bernoulli's
P(atm) + (rho)gh = P(atm) + 0.5(rho)v^2


The Attempt at a Solution


solution v = 2.81 m/s

I understand how to get the velocity at the bottom, but I was just wondering why atmospheric pressure acts on both the top and the bottom. I can grasp how atmospheric pressure acts on the bottom of the stream, but how does it act on the top of the stream?
 
sorry but can anyone answer / help me out?


bump (is this allowed?)