Physics- density

• What is the definition of density?

  Density is the amount of mass per unit volume of a substance.
• Why do lead and styrofoam have different densities despite being the same size?

  Lead has much more mass packed into the same volume compared to styrofoam.
• What is the formula for density?


  $\text{Density} =$$\frac{\text{Mass}}{\text{Volume}}$
• What units are typically used for mass and volume in the density formula?

  Mass is usually measured in grams (g) and volume in cubic centimeters (cm³) or milliliters (mL).
• What are the typical units for density?

  Density is typically expressed in grams per cubic centimeter (g/cm³) or grams per milliliter (g/mL).
• If an object has a mass of 30g and a volume of 10cm³, what is its density?


  $\text{Density} =$$\frac{30\,\text{g}}{10\,\text{cm}^3} =$$3\,\text{g/cm}^3$
• A block of metal has a mass of 135 grams and a volume of 50 milliliters. What is its density in g/mL?


  $\text{Density} =$$\frac{135\,\text{g}}{50\,\text{mL}} =$$2.7\,\text{g/mL}$
• If a liquid has a density of 0.8 g/mL and you have 250 mL of this liquid, what is its mass?

  Mass = Density × Volume = 0.8 g/mL × 250 mL = 200 g
• What are the relationships between mass, volume, and density?

  - Density is calculated as mass divided by volume. - If mass increases while volume remains constant, density increases. - If volume increases while mass remains constant, density decreases.
• How do you convert between units of density?

  - 1 mL = 1 cm³, so g/mL is equivalent to g/cm³. - To convert g/cm³ to kg/m³, multiply by 1000. - To convert g/mL to kg/L, multiply by 1000.