1. Density is mass per unit volume.
Chapter 3.1
Density is mass per unit volume.
This is made
from this.

2. Objects have mass and volume.
All objects are made of matter. Matter is anything that has mass and takes up space.
Mass: How much stuff is in the object.
Volume: How much space that object takes up.
Mass is different from volume.
PLASTIC VS METAL!!!!
Which spoon has more mass? More volume?

3. Measuring Mass
Measuring mass involves comparing the mass of an object with a standard unit of mass.
The standard unit of mass is kilogram (kg)
A balance measures in grams (g) g = kg
Move the decimal point 3 spots to the left!!!

4. Measuring Volume by Formula
Just like in math, you can measure the volume of a rectangular solid (box) using the equation:
Volume (of a box) = length x width x height
V = lwh

5. Other volume equations.. Taken from your math classes!
Cylinder Volume = πr2 x h
Sphere Volume = (4/3) x πr3
Cube Volume = s3 or s x s x s
Your math teacher will thank you if you know these!

6. Random Question #1
A NBA regulation Basketball has a diameter of 25 cm. What is the volume of the Basketball?
25 cm

7. Answer V = 4/3 πr3 V = (1.33) x (3.14) x (12.53)
V = cm3

8. Measuring Volume by Displacement
For objects with irregular shapes, you can measure how much liquid the object displaces (pushes out of the way).
Step 1. Add water to a graduated cylinder, note the volume of water.
Step 2. Push the object below the water and see the water level rise. Note the new volume of water.
Step 3. Subtract the volumes.
(New volume – original volume) = Volume of object

9. Displacement Volume of a Key
58 mL
Volume of Key is equal to the difference!
45 mL
45 mL

10. 1 mL = 1 cm3 Volume is measured in …
Liquid volume is measured in milliliters (mL).
Solids are measured by cubic centimeters (cm3) or cubic meters (m3).
1 mL = 1 cm3

11. Density is mass divided by volume.
Density- a measure of the amount of matter present in a given volume of a substance.
Density depends on both the mass and the volume of an object.
The density of a substance does not change!
A tiny bit of a substance will have the same density as a huge chunk of the same substance.

12. Calculating Density
Density is measured in g/cm3. (grams per centimeter cubed)
Mass = kg, but we want it in grams (g)
1.000 kg = grams
Move the decimal point 3 spots to the right!!!
Volume = mL or cm3

14. Comparing Densities Water has a density of 1
If a substance has a density less than 1 it will float in water. More than 1 it will sink.
FLOATS in Water
SINKS in Water

15. 3 4 12 2 Questions!!!! #1 What is the volume of the following shape?
This box? (in cm)
If it has a mass of 288g, what is its DENSITY?
#2 A. What is the volume of the rock? B. If it has a mass of 78 grams, what is its DENSITY? 3 4 12