# Principles of Technology

## Year End Review: Fluid Systems

### Fluid Force (1:2)

1. What is the Prime Mover in the Fluid System?

2. What are the 2 main types of fluids?

3. A volume of 350 cm3 of bean farts has a mass of 30 grams. Calculate the density of the resulting cloud of noxious fumes.

4. The height of a water tank is 750 feet above a valve. If the weight density of water is 62.4 lbs/ft3 what is the pressure at the valve?

5. A backhoe has a 4.75 in2 piston powered by a pump which produces 2250 lbs./in2 of hydraulic pressure. How much force is being produced?

### Fluid Work (2:2)

1. A pump needs 210,000 N·m of work to lift 51.3 m3 of fluid. What is the pressure difference?

2. What is the displacement of a hydraulic cylinder which completes 5540 ft·lb of work at a constant pressure of 11.3 lb/ft2?

3. A piston is displaced by a constant pressure of 150 N/m2. The cylinder moves a fluid volume of 0.025 m3 when the piston moves 11 cm.

3a. Calculate the work required to move the piston 11 cm.

3b. Calculate the force on the piston if the piston face has an area of 0.035 m2.

4. A pressure of 2250 lb/in2 is applied to the face of a piston in a closed hydraulic cylinder, causing a total force of 666.67 lb. on the face of the piston. Calculate the following:

4a. The area of the piston face.

4b. The diameter of the piston.

4c. The volume of fluid displaced when the piston moves 10 inches.

4d. The fluid work done by the piston when moving the 10 inches.

### Fluid Rate (3:2)

1. A tank holds 4,500 gallons of liquefied bat guano. What is the volume flow rate if it takes Travis 1.3 hours to suck it all out with a straw? Give the answer in gallons per minute.

2. Convert 91,054,022,010,602,030,003,674 to scientific notation.

3. Using scientific notation, multiply the above number by 71,209,051,002,334.

4. A river has an average depth of 2.34 meters and is 4.6 meters wide. How fast is the water moving if the volume flow rate of the river is 4,260 m3/sec?

### Fluid Resistance (4:2)

1. The resistance in an oil pipeline is 11.3 (lb/in2) / (gal/sec). 90 weight gear oil moves through the line at a rate of 11.50 gal/sec. What is the pressure difference?

2. Water flows through a 15 foot pipe at a flow rate of 11.5 ft3/sec. What is the resistance if it undergoes a pressure drop of 7.5 lb/ft2?

3. An air hose is 45 feet long, and has a flow rate of 25 gal/sec, and a pressure drop of 7.5 lb/in2.

5a. What is the flow rate of the hose?

5b. What will be the flow rate if an identical hose is connected, in series, to the first?

4. A pipe has a resistance (RF) equal to 2.25 (lb/in2) / (gal/min). What pressure drop is required to produce a flow rate of 350 gal/min?