Podcast
Questions and Answers
What is density defined as?
What is density defined as?
Mass per unit volume
What is the formula for calculating density?
What is the formula for calculating density?
𝜌 = 𝑑𝑚 / 𝑑𝑉
What is the density of air at 1 atm and 20 °C?
What is the density of air at 1 atm and 20 °C?
1.2 kg/m3
What is specific volume?
What is specific volume?
Signup and view all the answers
What does specific gravity (Relative density) represent?
What does specific gravity (Relative density) represent?
Signup and view all the answers
What is the formula for specific weight?
What is the formula for specific weight?
Signup and view all the answers
What is atmospheric pressure defined as?
What is atmospheric pressure defined as?
Signup and view all the answers
What is the formula for fluid pressure?
What is the formula for fluid pressure?
Signup and view all the answers
What happens to pressure as depth in a fluid increases?
What happens to pressure as depth in a fluid increases?
Signup and view all the answers
What is the unit of pressure expressed in?
What is the unit of pressure expressed in?
Signup and view all the answers
Study Notes
Density
- Density is defined as mass per unit volume.
- For a differential volume element of mass dm and volume dV, density can be expressed as: 𝜌 = 𝑑𝑚/𝑑𝑉
- Density depends on pressure and temperature
- For gases, density is directly proportional to pressure and inversely proportional to temperature: 𝜌 𝛼 𝑃 and 𝜌 𝛼 1/𝑇
- Density of air is about 1.2 kg/m^3 at 1 atm and 20 degrees Celsius
- Density of water is about 998 kg/m^3 at 4 degrees Celsius
Specific Volume
- Specific volume is the volume per unit mass
- It is the inverse of density: 𝜐 = 1/𝜌 = 𝑉/𝑚 (units: m^3/kg)
Specific Gravity
- Specific gravity (SG) is the ratio of the density of a substance to the density of a reference substance, typically water at 4°C (𝜌𝑤 = 1000 kg/m^3)
- Can be calculated as: 𝑆𝐺 = 𝜌/𝜌𝑤𝑎𝑡𝑒𝑟
Specific Weight
- Specific weight (γ) is the weight of a unit volume of a substance.
- Can be calculated as: 𝛾 = 𝑔𝜌 (units: N/m^3)
Pressure
- Pressure is the force exerted by a fluid on a unit area.
- It acts in all directions.
- Calculated as: 𝑃 = 𝐅/𝐀 (units: N/m^2)
- Pressure results from the collision of fluid molecules with container walls, imparting momentum.
- Pressure increases with depth due to the added weight of the fluid above.
Atmospheric Pressure
- Atmospheric pressure is the weight exerted by the atmosphere on a unit area of surface.
- Standard atmospheric pressure is 1.013 * 10^5 N/m^2.
Fluid Pressure
- Fluid pressure at a depth h is calculated with the equation: 𝑃 = 𝑃𝑎𝑡𝑚 + 𝜌𝑔ℎ .
- This accounts for the weight of the fluid above the point where the pressure is measured.
- Variation of pressure with depth is calculated as: 𝑃 = 𝜌𝑔ℎ = 𝛾ℎ
- The pressure of a fluid at rest increases linearly with depth.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the fundamental concepts of density, specific volume, specific gravity, specific weight, and pressure. This quiz covers the relationships between mass, volume, and temperature, as well as the calculations involved in understanding these properties. Test your knowledge on these essential topics in physics!
