# density

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• Created by: tia5sos
• Created on: 26-11-20 16:31
• density
• density is mass per unit volume
• Density is a measure of the 'compactness' of a substance. It relates the mass of a substance to how much space it takes up.
• the units of density are g/cm      or kg/m
• 1. The density of an object depends on what it's made of. Density doesn't vary with size or shape.
• 2. The average density of an object determines whether it floats or sinks - a solid object will float on a fluid if it has a lower average density than the fluid
• you can measure the density of solids and liquids
• 1. to measure the density of a substance, measure the mass and volume of a sample of the substance and use the formula density = mass divided by volume
• 2. You can measure the mass of a solid or liquid using a mass balance
• 3. to measure the volume of a liquid, you can just pour it into a measuring cylinder
• 4. 1ml = 1cm   if you need to convert a volume into other units, e.g. m      remember you need to cube the scaling factor for converting distance units to get the scaling factor for converting volume units.
• for example, to convert 50cm       into m     = 50 divided by 1,000,000 (as there are 100cm in 1m). So 50cm    =50 divided by 1,000,000 = 5 x 10      m
• 5. if you want to measure the volume of a solid cuboid, measure its length, width, and height, then multiply them together. To find the volume of a solid cylinder, measure the diameter of one of the circles at the base, then halve this to give the radius. Then measure the cylinders height, and use the formula volume =            x radius       x height
• 6. an object submerged in water will displace a volume of water equal to its own volume. You can use this to find the volume of any object, for example using a eureka (Archimedes) can