 # Density Review.

## Presentation on theme: "Density Review."— Presentation transcript:

Density Review

What is the formula for Density?
Mass Density = Volume Density is the mass of something divided by its volume.

What is the unit for Mass?
The unit for the mass of something is always expressed in GRAMS Examples: A pink eraser has a mass of 23.1 g A roll of Smarties has a mass 7.3g

What are the units which represent the volume of something?
Milliliters (mL) is one unit that represents volume. Liquids are measured in mL. For example, water sometimes comes in 500 mL bottles. Irregularly shaped objects are also measured in mL. For example, a marble has a volume of 6 mL

Units of volume, continued
Cubic Centimeters (cm3)is the other unit that represents volume. To get the volume of a regularly shaped object, you will need to multiply the base times the width times the height (B x W x H). If you are given a length in cm, you will need to multiply this number by itself 3 times to get cm3 cm x cm x cm = cm3

Steps to calculating Density
Determine the mass Determine the volume Divide the mass by the volume Be sure to include the correct units

Solving Density Problems
Identify the mass of the object. Identify the volume of the object (hint: you may have to do some math… sometimes you will have to subtract the starting volume from the ending volume if you are using mL. Sometimes you will have to multiply the sides of an object in order to get cm3

Density Problems A student measures the mass of an 8 cm3 block of brown sugar to be 12.9 g. What is the density of the brown sugar? What is the mass? m = 12.9 g What is the volume v = 8 cm3 Calculate the Density Density = 12.9 g = g or 1.6 g/cm3 8 cm3 cm3