Conceptual question: Atmospheric pressure

AI Thread Summary
Atmospheric pressure affects both the top and bottom of the water stream due to the principle that pressure acts uniformly in all directions. At the top, atmospheric pressure contributes to the overall pressure exerted on the water, while at the bottom, it balances the pressure from the water column. The Bernoulli equation accounts for energy conservation, where kinetic energy is represented by the velocity term. The inquiry about the kinetic energy term reflects a common confusion regarding the application of Bernoulli's principle. Understanding these concepts clarifies the role of atmospheric pressure in fluid dynamics.
johnj7
Messages
27
Reaction score
0

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?
 
Physics news on Phys.org
sorry but can anyone answer / help me out?


bump (is this allowed?)
 
Shouldn't there be a kinetic energy term on the left-hand side of the equation?
 

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Solving Fluid Statics Problem: Accounting for Atmospheric Pressure
Replies
9
Views
2K
Conceptual Issue Dealing With Atmospheric Pressure
Replies
4
Views
2K
Pressure of water coming out of a hose nozzle
Replies
7
Views
987
Atmospheric Pressure on Shaft of piston cylinder assembly
Replies
3
Views
5K
Clarifying the Definition Total/Stagnation Pressure (p₀) in Bernoulli'
Replies
2
Views
951
Pressure in Liquids: How Does It Affect Volume?
Replies
20
Views
2K
How Does Atmospheric Pressure Affect Water Stream Shrinkage?
Replies
3
Views
1K
Chimney effect and pressure difference
Replies
10
Views
2K
Gauge pressure and atmospheric pressure
Replies
2
Views
2K
Forces due to atmospheric pressure won't cancel in an open tank
Replies
13
Views
3K

Hot Threads

Recent Insights

Back
Top