about bernoulli's principle

1. 05-05 FLOW RATE AND BERNOULLI’S
EQUATION
In this lesson you will…
• Calculate flow rate.
• Describe incompressible fluids.
• Explain the consequences of the equation of continuity.
• Explain the terms in Bernoulli’s equation.
• Explain how Bernoulli’s equation is related to conservation of energy.
• Calculate with Bernoulli’s principle.
• List some applications of Bernoulli’s principle.

2. 05-05 FLOW RATE AND BERNOULLI’S EQUATION
SAll the motion observed in this lab was caused by differences in pressure.
SIn all the experiments, which way is the object move: towards or away
from the moving air?
SAn object will move from higher to lower pressure. Where was the
pressure the lowest: moving or still air?
SWhere was the pressure the highest?

3. 05-05 FLOW RATE AND BERNOULLI’S EQUATION
SFlow Rate
J𝑄 =
!
"
ŠQ = Flow rate
ŠV = Volume of fluid
Št = time
S 𝑄 =
!
"
=
#$
"
= 𝐴𝑣
JA = cross-section area
J𝑣 = average velocity of fluid

4. 05-05 FLOW RATE AND BERNOULLI’S EQUATION
SSince flow rate is constant for a
given moving fluid
SEquation of continuity
J𝜌%𝐴%𝑣% = 𝜌&𝐴&𝑣&
SIf incompressible
J𝐴%𝑣% = 𝐴&𝑣&
SIf incompressible and several
branches
J𝑛%𝐴%𝑣% = 𝑛&𝐴&𝑣&

5. 05-05 FLOW RATE AND BERNOULLI’S EQUATION
A B C
SWhere does the water flow the fastest?

6. 05-05 FLOW RATE AND BERNOULLI’S EQUATION
SA garden hose has a diameter of 2 cm and water enters it at 0.5
m/s. You block 90% of the end of the hose with your thumb. How
fast does the water exit the hose?

7. SHow many cubic meters of blood does the heart pump in a 75-
year lifetime, assuming the average flow rate is 5.00 L/min?

8. SA nozzle with a radius of 0.250 cm is attached to a garden hose
with a radius of 0.900 cm. The flow rate through hose and
nozzle is 0.500 L/s. Calculate the speed of the water (a) in the
hose and (b) in the nozzle