1. Daily Science August 29 Write the abbreviation for microliters.
How many decimeters are in 450 Hectometers
You are baking using a recipe from the UK. It calls for 48 ounces of butter. How many pounds is that (16 oz= 1 lb; 1 lb=453.6 g)

2. Density
Pg. 15

3. Density
Density is a ratio that compares the mass of an object to its volume.
density= mass/volume
d= m/v
Units: g/cm3 or g/mL

4. Calculating Density in a Lab
Use water displacement method
Record starting volume, place object in, record final volume
Calculate mass
Can also sometimes measure
volume using a ruler

5. Practice Problems
Calculate the density of a rock that has a mass of 5.6 g if when placed in a graduated cylinder that started at 10 mL, rose to 13 mL.
Find the volume of a piece of aluminum wire that has a mass of 4 g and a density of 6.6 g/mL.

6. Percent Error
Percent error is the ratio of an error to an accepted value.
Percent error=
{(actual value-experimental value)/actual value} x 100

7. PE practice problems
You calculate the density of a piece of metal to be 3.4 g/mL. The actual density is 3.7 g/mL. Calculate the percent error.