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Density. If density is a measure of how tightly the matter within an object is packed together which of the cubes above has the greatest density?. Density. Density is a physical property of a substance that is used to identify that substance.
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Density If density is a measure of how tightly the matter within an object is packed together which of the cubes above has the greatest density?
Density • Density is a physical property of a substance that is used to identify that substance. • The size of the object does not change the density. The density of Lead is going to be the same. Density of Lead Density of Lead Density of Lead
Density is a measure of a substance’s mass per unit volume • The word “per” means to divide!!! • In our formula to the left you can abbreviate the terms with the first letter. • THESE FORMULAS CAN ALWAYS BE FOUND ON YOUR REFERENCE SHEET! OR
We use one of two methods to remember how to calculate density. Method 1: I Density
Density Triangle Method 2: M D V There is only ONE rule to using the density triangle. Cover what you are looking for!
Identifying your units! The base unit for mass (m) of an object is grams (g). The base unit for volume of a solid is cubic centimeters ( ). The base unit for volume of a liquid is milliliters (ml)
The two types of solids: Regular solid: a solid which the sides can be measured using a ruler to get the volume. V= L x W x H Irregular solid: a solid with sides that are not capable of being measured with a ruler. Example: odd shaped rock For this type of object we use WATER DISPLACEMENT
Water Displacement To Find the volume of an irregular solid: Rule of Thumb: 1. Using a graduated cylinder fill with water to a specific amount such as 100 ml. 2. Slowly lower object in to the graduated cylinder (the water will rise). 3. Subtract the final amount from the initial amount and that will be the volume of the object. 4. Convert from ml to . 1 ml = 1cm^3
Practice Problems • A piece of wood that measures 3.0 cm by 6.0 cm by 4.0 cm has a mass of 80.0 grams. What is the density of the wood? Would the piece of wood float in water? (volume = L x W x H)
Practice Problem 2 • A 800g boulder has a density of 8 g/cm3. What is the volume of the boulder?
H.O.T Practice Problem • Archimedes was commissioned to determine if the crown given to the king was pure gold or not. If the crown had a mass of 882 grams and displaced 50 mL of water, was the crown pure gold? Show the calculation, the density of Pure Gold is 19.3 g/cm^3.