1. DENSITY

2. Density and Buoyancy- Key Points
Density is the ratio of mass to volume
The solid state of a substance is usually denser than liquid state. The liquid state is denser than the gas state.
What is Density? Video

3. BUOYANCY BUOYANCY = the ability to float in a fluid.
Examples of fluids = water, air
BUOYANT FORCE = the upward force that acts on a submerged object.
It acts opposite of gravity

4. Why do Boats Float? 1st-Boats are designed to minimize water entry
2nd The water density vs. the boat’s density (metal of the boat, people, etc) is less than the water
Result: THE BOAT FLOATS

6. A WHICH ONE IS MORE LIKELY TO FLOAT?
Mass = 90 kg
Mass = 90 kg B A
WHICH ONE IS MORE
LIKELY TO FLOAT?

7. DENSITY d = m / v DENSITY OF WATER = 1 g/cm3
If the object has a higher density, it sinks.
If the object has a lower density, it floats.
if the object has the same density, it flinks (floats in the middle of the water).

8. Density and Temperature
CHANGING DENSITY BY ADDING HEAT
RESULT:
Particles move faster
Particles spread apart
Volume increases
Density decreases
FREEZING A LIQUID
RESULT:
Particles move slightly further apart
Increasing volume
Decreasing density

9. Measuring Units Density of liquids = Density of Gas =
Density of Solids =
Grams per milliliter (g/ml) Kilograms per liter (kg/L) Grams per cubic centimeter (g/cm3)

10. Calculating Density, Mass, Volume
D= DENSITY M= MASS V=VOLUME Density= M V Mass= D x V Volume= M D

11. Sample Equation A 20ml sample of oil has a mass of 1. 76g
Sample Equation A 20ml sample of oil has a mass of 1.76g. What is its density?
G: V=2.0 mL M= 1.76g R: Density=? A= D=M V S: mL = 0.88g/mL S: The oil has a density of 0.88g/mL
Steps: Given Required to find Analysis (Formula) Solution Statement

12. Sample Equation A liquid as a mass of 450g and a density of 0. 90g/ml
Sample Equation A liquid as a mass of 450g and a density of 0.90g/ml. What is its volume?
G:M=450g D= 0.90g/mL R: V=? A= V=M D S: 450g 0.90g/mL = 500/mL S: The volume of the liquid is 500/mL
Steps: Given Required to find Analysis (Formula) Solution Statement

13. Homework
Work on Questions 1-5