1. Use of Fluids & Fluids and Living Things
Chapter 5 & 6 Review
Use of Fluids & Fluids and Living Things

2. Category: Pressure
What is the equation for pressure (p=) and what does each letter stand for. Include units.
p = force / area
p = pressure (N/cm2 or N/m2 or Pa)
F = force (Newton – N)
A = area (cm2 or m2)

3. Category: Fluid Systems
Describe how oil from a tank can lift up a car. Use the words hydraulic fluid, conductor, cylinder, pump, and piston in your explanation.
The hydraulic fluid, oil, is held in a tank. It is sent along a conductor (hose/tube/pipe) to a pump, where it is pushed into a cylinder. The fluid pushes up the piston in the cylinder like a plunger moving inside a syringe, which moves the car up.

4. Category: Fluid Systems
What type of pressurized fluid system does your respiratory system resemble?
A pneumatic system.

5. Category: Pressure
What is the unit “pascal” used for (what does it measure?) and what is it equivalent to in terms of units for force and area?
Pascal is used as a unit of pressure.
It is equivalent to 1 N/m2.

6. What is the purpose of a valve in a fluid system?
Category: Fluid Systems
What is the purpose of a valve in a fluid system?
To control the flow of fluid by keeping it flowing in a certain direction or to stop the flow altogether.

7. What causes atmospheric pressure?
Category: Pressure
What causes atmospheric pressure?
The force of gravity exerted on all the particles in the atmosphere.
This weight of air pushes down on itself and Earth’s surface.

8. Category: Confined Fluids
From the following list, name that or those which use(s) a hydraulic system: car brakes, tire inflator, crane, nail gun.
Car brakes and a crane.
The others use pneumatic systems.

9. Category: Fluid Systems
Hydraulic systems use pumps to keep the fluid flowing, whereas pneumatic systems use __________________ to continue delivering the air in the system at the correct pressure.
Air compressors.

10. Why are gases compressible?
Category: Confined Fluids
Why are gases compressible?
The particles in a gas are far apart, so they can be pushed closer together (compressed). This reduces the volume of the gas.

11. Category: Pressure
Why is it easier to cross a snow-covered field in snowshoes rather than boots?
With snowshoes, your weight (force) is being distributed over a much larger area. This results in lower pressure on the snow so that you don’t sink down as much.

12. Category: Pressure
What happens to fluid pressure as you dive deeper down in the lake or ocean?
Fluid pressure increases because there is more weight of water pushing down on you.

13. Compare liquids and gases in terms of their compressibility.
Category: Confined Fluids
Compare liquids and gases in terms of their compressibility.
Liquids are nearly incompressible. Their particles are too close together to be pushed even closer. Gases are compressible because the particles are far apart and can be pushed closer together.

14. What does Pa stand for? What does kPa stand for?
Category: Pressure
What does Pa stand for? What does kPa stand for?
Pa = pascal (N/m2)
kPa = kilopascal (1000 Pa)

15. Category: Confined Fluids
What happens to the pressure of a confined fluid if the volume is held constant but the temperature is increased?
The pressure of the fluid increases.
The particles will hit the sides of the container more often with a rise in temperature, corresponding to a higher pressure.

16. Category: Confined Fluids
List one benefit of using fluid-powered systems (hydraulic and pneumatic systems).
- They can do heavy or delicate work quickly and efficiently
- They can perform dangerous jobs, making the workplace a safer place

17. What is a conductor in a hydraulic or pneumatic system?
Category: Fluid Systems
What is a conductor in a hydraulic or pneumatic system?
A conductor is a hose, tube, or pipe that carries the hydraulic fluid or, in a pneumatic system, the gas.

18. Which system in your body acts as a hydraulic system?
Category: Fluid Systems
Which system in your body acts as a hydraulic system?
The circulatory system.

19. What is a pump used for in a fluid system?
Category: Fluid Systems
What is a pump used for in a fluid system?
A pump is used to create a flow of fluid (often against gravity).

20. What is pressure? Category: Pressure
The force (Newtons) per unit of area (m2 or cm2).

21. Category: Fluid Systems
In the circulatory system, which parts act as the pump, the hydraulic fluid, and the conductors?
The heart acts as the pump, the blood acts as hydraulic fluid, and the conductors are the blood vessels (arteries/veins/capillaries).

22. Category: Pressure
Find the pressure exerted on the ground if 100 cm2 of a 500 N brick is touching the ground. Include correct units.
p = F / A = 500 / 100 = 5 N/cm2

23. Why is there no delay when using hydraulic systems?
Category: Confined Fluids
Why is there no delay when using hydraulic systems?
The particles of a liquid are very close together; therefore, the force is instantly transmitted from one particle to the next.

24. Category: Pressure
Where would you find the lowest atmospheric pressure: at sea level or at the peak of Mount Everest?
At the peak of Mount Everest. As elevation increases, atmospheric pressure decreases.
At higher altitudes, there is not much weight of air pushing down on itself.

25. What is a hydraulic system?
Category: Confined Fluids
What is a hydraulic system?
A confined, pressurized system that uses moving liquids.