1. U3f – L2
March3, 2010
DRILL
Using the chart of information you recorded yesterday, add two new columns onto your chart.
Title one column “1/P” and calculate 1/P for each of the pressures in your chart (to 3rd decimal place).
Title the second column “P x V” and calculate P x V for each of the volumes and pressures in your chart (to nearest whole number).

2. Principles of Fluid Technology
U3f – L2
Principles of Fluid Technology
Your chart should now look like this:

3. FLUID TECHNOLOGY What is a FLUID?
U3f - L1
FLUID TECHNOLOGY
What is a FLUID?
A substance (as a liquid or a gas) that conforms to the outline of its container
Fluid Systems have 2 things in common:
They contain a fluid, either gas (pneumatics) or liquid (hydraulics)
They contain a pressure difference that creates a net force

4. What is Fluid Technology?
U3f - L1
REVIEW
What is Fluid Technology?
The technology of using fluid, either gas (pneumatics) or liquid (hydraulic) to apply force or to transport.
Example applications:
Air brakes on a truck,
Tires on a car,
Airfoils on an airplane,
Warm-air heating ducts,
Hydraulic jack,
Plumbing in a school
Hydro-electric dam

5. U3f - L1

6. Principles of Fluid Technology
U3f - L1
Principles of Fluid Technology
Graph your Volume and Pressure data
Make volume the independent
Make pressure the dependent
Start both at zero
X-axis
Y-axis
What is the data range?
Volume: 9-30 mL
Pressure: psi
Pressure (psi)
Volume (mL)

7. Principles of Fluid Technology
U3f - L1
Principles of Fluid Technology
Your graph should like the graph below.
What can you say about the relationship between volume and pressure?
As volume increases, pressure decreases
Is this a proportional or inversely proportional relationship?
As Volume goes up, Pressure goes down
As Pressure goes up, Volume goes down

8. Principles of Fluid Technology
U3f - L1
Principles of Fluid Technology
How is this represented mathematically?
V / P or
P / V
Now graph Volume vs. 1/P
Data range for volume is same; data range for 1/P is .018 to .058
Volume is independent
1/P is dependent
[Volume is proportional to 1/P] a
[Pressure is proportional to 1/V] a

9. Principles of Fluid Technology
U3f - L1
Principles of Fluid Technology
Is this representative of a proportional relationship?

10. Principles of Fluid Technology
U3f – L2
Principles of Fluid Technology
Back to your chart.
What do you notice about the values for P x V?
Under constant temperature, the product of pressure and volume for a fluid is a constant.
P V = k

11. U3f – L2
Boyle’s Law
Robert Boyle ( ) – from Ireland, chemist, physicist, and inventor
Boyle’s Law – the pressure and volume of an ideal gas are inversely proportional
Increase Pressure
Decrease Volume
Increase Volume
Decrease Pressure
PV = k
P1V1 = P2V2

12. U3f – L2
BOYLE’s LAW
PV = k
P1V1 = P2V2

13. Problems (copy these problems):
U3f – L2
BOYLE’s LAW
Problems (copy these problems):
A gas system has initial pressure and volume of 60 psi and 8 L. If the volume changes to 5 L, what will the resultant pressure be in psi?
A sample of helium gas is compressed from 200 cm3 to cm3. Its pressure is now 3 psi. What was the original pressure of the helium?
P1V1 = P2V2

14. #1 Solution: BOYLE’s LAW Does the answer make sense?
U3f – L2
BOYLE’s LAW
#1 Solution:
Step 1: Write given information
P1 = 60 psi
V1 = 8 L
P2 = ?
V2 = 5 L
Step 2: Write the formula and solve
P1V1 = P2V2
(60 psi) x (8 L) = P2 x (5 L)
480 psi*L = P2 x (5L)
5L L
P2 = 96 psi
Does the answer make sense?

15. #2 Solution: BOYLE’s LAW Does the answer make sense?
U3f – L2
BOYLE’s LAW
#2 Solution:
Step 1: Write given information
P1 = ?
V1 = 200 cm3
P2 = 3 psi
V2 = cm3
Step 2: Write the formula and solve
P1V1 = P2V2
P1 x (200 cm3) = (3 psi) x (0.240 cm3)
P1 x (200 cm3) = .72 psi*cm3
200 cm cm3
P1 = psi
Does the answer make sense?