Unit A Section A4 Introduction Fluids and Technology
Completion requirements
Section 4: The properties of fluids provide many technology solutions.
Unit A: Section 4 – Introduction
Figure A.S.4.1 – Mountain bikes have wide, lower pressure tires.
Figure A.S.4.2 – Road bicycles have thin, higher pressure tires.
Figure A.S.4.3 – Car tires are filled with air.
Tire Pressure
Air-inflated rubber tires were invented in the late 1800’s. Inflated tires have a higher air pressure than the outside atmosphere. A higher air tire pressure is needed to support the weight of the car or bicyclist.
Inflated rubber tires are better shock absorbers than solid wheels. Air is compressible, which means it can be squeezed into a smaller space. When a tire bumps against the ground, the air inside the tire absorbs the shock and is compressed, instead of the vehicle’s body taking the shock. This makes for a smoother ride.
Air-inflated rubber tires were invented in the late 1800’s. Inflated tires have a higher air pressure than the outside atmosphere. A higher air tire pressure is needed to support the weight of the car or bicyclist.
Inflated rubber tires are better shock absorbers than solid wheels. Air is compressible, which means it can be squeezed into a smaller space. When a tire bumps against the ground, the air inside the tire absorbs the shock and is compressed, instead of the vehicle’s body taking the shock. This makes for a smoother ride.
Watch More
Pump Up Your Tires
The tires on race cars are inflated to a lower pressure than most other tires. Watch this video to find out why.
The tires on race cars are inflated to a lower pressure than most other tires. Watch this video to find out why.
Airplane tires need to be very strong to withstand extreme heat and pressure while taking off and landing. Watch this video to see an airplane tire being tested with extreme pressure.
Words to Think About:
Check out the word cloud below. It pictures the important words that you are going to learn in this section. Watch for these words, and combinations of these words, as you read. When you see them highlighted, you can click on them to learn more about
what the word means. You can also visit the course glossary and read definitions for all of these words.
Lessons in This Section
Lesson A11: Fluid Technologies: Solubility
Key Question – How do we use solubility to extract substances from mixtures?
Lesson A12: Fluid Technologies: Density and Viscosity
Key Question – How do density and viscosity affect the motion of objects?
Lesson A13: Pumps, Valves, and PipelinesKey Question – How are fluids transported from one location to another?
Lesson A14: Going Places with Fluids
Key Question – How do different transportation machines use fluids to operate?
Reading and Materials for This Section
Science in Action 8
Reading: Pages 62–74
Materials Lists for Unit:
Figure A.S.4.4 – Compressed air hoses at gas stations put high pressure air into tires.
Figure A.S.4.5 – Muscle power can also be used to add air pressure to tires.
Figure A.S.4.6 – A tire gauge measures air pressure in tires.
Filling Tires
Air compressors and pumps are machines that create high air pressure. We use air compressors and pumps to fill tires. If you look closely on the edge of a car tire, you will see a number that indicates the maximum recommended tire pressure. In Canada, we officially use the metric system to measure pressure in kilopascals, or kPa. However, on a tire, you will likely also see a number for psi, or pounds per square inch, which is the pressure measurement used in the United States. Canadians often use psi to measure tire pressure.
The markings on car tires tell you the maximum air pressure that a tire can handle, but you should actually fill your tires to a lower amount. Car manuals contain the manufacturer’s pressure recommendation.
Bicycle tires usually have a range of acceptable pressures printed on the side of the tire. Bicycle tire pressure depends on the tire width. Thin road bicycle tires usually have a pressure between 80 and 120 psi. Fat mountain bike tires usually have a pressure between 30 and 50 psi.
Air compressors and pumps are machines that create high air pressure. We use air compressors and pumps to fill tires. If you look closely on the edge of a car tire, you will see a number that indicates the maximum recommended tire pressure. In Canada, we officially use the metric system to measure pressure in kilopascals, or kPa. However, on a tire, you will likely also see a number for psi, or pounds per square inch, which is the pressure measurement used in the United States. Canadians often use psi to measure tire pressure.
The markings on car tires tell you the maximum air pressure that a tire can handle, but you should actually fill your tires to a lower amount. Car manuals contain the manufacturer’s pressure recommendation.
Bicycle tires usually have a range of acceptable pressures printed on the side of the tire. Bicycle tire pressure depends on the tire width. Thin road bicycle tires usually have a pressure between 80 and 120 psi. Fat mountain bike tires usually have a pressure between 30 and 50 psi.
Watch More
Tire Pressure Safety
Watch this video to learn how to check tire pressure and fill tires properly.
Watch this video to learn how to check tire pressure and fill tires properly.