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Density

3,993 bytes added, 15:25, 5 March 2019
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: An [[object]] with a small amount of [[mass]] spread over a large [[Volume (Space)|volume]] is said to have a low [[density]].
: The [[SI Unit|units]] of [[density]] are kg/m<sup>3</sup>.
 
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|[[File:ParticleModelSolidLiquidGas.png|center|500px]]
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| style="height:20px; width:200px; text-align:center;" |[[Solid]]s are the most dense [[State of Matter|state of matter]] because there are a large number of [[particle]]s in a certain [[Volume (Space)|volume]] and [[gas]]es are the least '''dense''' [[State of Matter|state of matter]] because there are a small number of [[particle]]s in a the same [[Volume (Space)|volume]].
|}
 
===Density and Floating===
: If an [[object]] is more '''dense''' than [[water]] it will sink.
: If an [[object]] is less '''dense''' than [[water]] it will rise through [[water]] and float on the surface.
 
===Equation===
: Density = Mass/volume
:<math>\rho = \frac{m}{V}</math>
Where:
: ρ = [[density]]
: m = [[mass]]
: V = [[Volume (Space)|volume]]
 
===Example Calculations===
{| class="wikitable"
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| style="height:20px; width:200px; text-align:center;" |'''5000[[kg]] of [[Iron]] has a [[volume]] of 0.635m<sup>3</sup>. Calculate the density of [[Iron]].'''
| style="height:20px; width:200px; text-align:center;" |'''A 50,000cm<sup>3</sup> container of [[water]] is full with a 50[[kg]] [[mass]] of [[water]]. Calculate the density of [[water]].'''
| style="height:20px; width:200px; text-align:center;" |'''A 200,000cm<sup>3</sup> [[volume]] of [[air]] has a [[mass]] of 245[[g]]. Calculate the density of [[air]].
|-
| style="height:20px; width:200px; text-align:left;" |
[[Mass]] = 5000[[kg]]
 
[[Volume (Space)|Volume]] = 0.635m<sup>3</sup>
 
:<math>\rho = \frac{m}{V}</math>
 
:<math>\rho = \frac{5000}{0.635}</math>
 
:<math>\rho = 7874kg/m^3</math>
| style="height:20px; width:200px; text-align:left;" |
[[Mass]] = 50[[kg]]
 
[[Volume (Space)|Volume]] = 50,000cm<sup>3</sup> = 0.05m<sup>3</sup>
 
:<math>\rho = \frac{m}{V}</math>
 
:<math>\rho = \frac{50}{0.05}</math>
 
:<math>\rho = 1000kg/m^3</math>
| style="height:20px; width:200px; text-align:left;" |
[[Mass]] = 245[[g]] = 0.245[[kg]]
 
[[Volume (Space)|Volume]] = 200,000cm<sup>3</sup> = 0.2m<sup>3</sup>
 
:<math>\rho = \frac{m}{V}</math>
 
:<math>\rho = \frac{0.245}{0.2}</math>
 
:<math>\rho = 1.225kg/m^3</math>
|}
 
==Key Stage 4==
===Meaning===
[[Density]] is the amount of [[mass]] per [[unit]] [[Volume (Space)|volume]] of an [[object]].
 
===About Density===
: An [[object]] with a large amount of [[mass]] in a small [[Volume (Space)|volume]] is said to have a high [[density]].
: An [[object]] with a small amount of [[mass]] spread over a large [[Volume (Space)|volume]] is said to have a low [[density]].
: The [[SI Unit|units]] of [[density]] are kg/m<sup>3</sup>.
 
===Finding the Density===
====Finding The Density of a Regular Object====
: A regular [[object]] is a [[solid]] in the shape of a [[cuboid]].
#Measure the [[mass]] of the [[cuboid]] using an [[Electronic Balance]] or [[Measuring Scale]].
#Measure the length, width and height of the [[cuboid]].
#Multiply the length, width and height to calculate the [[Volume (Space)|volume]].
#Divide the [[mass]] by the [[Volume (Space)|volume]] of the [[cuboid]] to calculate the [[density]].
 
====Finding The Density of an Irregular Object====
: An irregular [[object]] is a [[solid]] whose shape prevents the sides being measured by a [[ruler]].
#Measure the [[mass]] of the [[object]] using an [[Electronic Balance]] or [[Measuring Scale]].
#Fill a [[Measuring Cylinder|measuring cylinder]] with enough [[water]] to [[submerse]] the [[object]].
#Take a reading of the [[Volume (Space)|volume]] of [[water]] in the [[Measuring Cylinder]].
#Place the [[object]] in the [[Measuring Cylinder]] and ensure it is [[submerse]]d.
#Take a reading of the [[Volume (Space)|volume]] of [[water]] + [[object]] in the [[Measuring Cylinder]].
#Subtract the [[Volume (Space)|volume]] of [[water]] from the [[Volume (Space)|volume]] of [[water]] + [[object]] to find the [[Volume (Space)|volume]] of the [[object]].
#Divide the [[mass]] by the [[Volume (Space)|volume]] of the [[object]] to calculate the [[density]].
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