Under pressure Flashcards
What is pressure?
It is the amount of force pushing against a given area. Its unit is N/m^2 or Pascal (Pa). Pressure = Force/Area
What is gas pressure?
It is the pressure that results from the collision of gas particles with an object. How much pressure a gas exerts depends on the amount of gas. The more gas particles there are the greater the pressure.
What are the gas laws?
They describe the relationship between the pressure, volume, and temperature of a given amount of gas. They are named after the scientist who discovered them
What is Boyle’s law
Discovered by Robert Boyle. If the temperature of a gas is held constant, increasing the volume of the gas decreases its pressure.
As volume increases, the pressure of the gas decreases because pressure and volume are inversely proportional.
What is Charles’s law?
Discovered by Jaques Charles. If the pressure of gas is held constant, increasing the temperature of gas increases its volume.
What is Amonton’s law?
Discovered by Guillaume Amontons. If the volume of a gas is held constant, increasing the temperature increases of a gas increases its pressure.
What is Bernoulli’s principle and its applications?
Bernoulli’s law states that the pressure of a moving fluid such as air is less when the fluid is moving faster. It explains how wings of airplanes or birds causes the air below them to move slow. This makes the pressure above lesser than the pressure below them keeping them above the ground. A spoiler on a car is a upside down wing
What is the atmosphere
The atmosphere is a blanket of gases that surrounds the planet. It protects and sustains life. The mixture of gasses in the atmosphere is called air.
What gasses are in the atmosphere?
- Nitrogen makes up about 78% of the earths atmosphere. It is released in the air by volcanoes and decaying matter.
- Oxygen makes up 21% of the Earth’s atmosphere. Humans and other living things need oxygen to survive
- The remaining 1% is made of 0.93% Argon and 0.04% CO2. The rest are trace gasses.
What is the nitrogen cycle
Nitrogen is used to make protein in living things. Nitrogen is changed to nitrogen containing molecules by bacteria in soil. Plants absorb the molecules and use them to make protein. Humans and animals eat the protein. Bacteria in the soil eventually return nitrogen to the atmosphere.
Atmosphere of Mercury, Venus, Earth, Mars
Mercury - No atmosphere
Venus - Atmosphere with 96% CO2
Earth - 78% Nitrogen
Mars - 95% CO2
How did oxygen enter the Earths atmosphere?
Organisms like plants used the energy of the sun to survive. This process is called photosynthesis and also used CO2. In this process they released oxygen filling up the atmosphere with it.
How is carbon stored?
Bodies of living things are mostly made up of carbon. Plants take in carbon from the atmosphere to build tissues. Carbon enters the atmosphere when organisms exhale and decompose. Long living organisms store carbon for long, when they die the carbon gets stored in the ground. Organisms also use carbon to make their shells. This helps make fossil fuels.
Pressure in the atmosphere
Atmospheric pressure is a measure of the force per unit area of air molecules in the atmosphere at a given altitude.
Molecules closest to Earth’s surface are packed together very densely. This is because the weight of the molecules above presses down, creating atmospheric pressure. The pressure is greatest at sea level
Altitude and air pressure
Altitude is a measure of the distance of an object above sea level. As the altitude increases, the density of the air molecules decreases as there are fewer molecules pushing down and a weaker gravitational pull.