KS3+Density+and+Pressure

media type="youtube" key="ijj58xD5fDI" width="560" height="315" [|How taking a bath led to Archimedes' principle] - Mark Salata [|TED-Ed] Published on 6 Sep 2012 [|Density of Noble gases] from www.bbc.co.uk || [|Density of Group 1 element] from chem.libretexts.org ||
 * Density and pressure **
 * [[image:Density of group 0 elements.PNG width="453" height="283"]]

=**Measuring volume by displacement**=

Objects with irregular shapes cannot easily have their volume measured so it is done by displacement of water. Describe the steps of how to find the volume of an irregular object using displacement can. media type="youtube" key="kBF1PTgRjbQ" width="560" height="315" [|Measuring Volume by Displacement] [|Robert Hildebrand] Published on 19 Sep 2014 Density = Mass / Volume
 * [[image:sciencelanguagegallery/displace.gif]] || [[image:sciencelanguagegallery/volume-measurement-irregular-solids.jpg width="380" height="324"]] ||
 * Substance || Mass __(g)__ || Volume __(cm)__ || Density __(g/cm 3 )__ ||
 * Aluminum ||  ||   ||   ||
 * Perspex ||  ||   ||   ||
 * Slate ||  ||   ||   ||
 * Hardwood ||  ||   ||   ||
 * Lead ||  ||   ||   ||
 * Polystyrene ||  ||   ||   ||
 * Marble ||  ||   ||   ||
 * Brass ||  ||   ||   ||
 * Glass ||  ||   ||   ||

Lead was the most dense with a density of 7.94 out of the materials we measured. Hardwood was the least dense with a density of 0.67. The density of the concentrated sugar water was 1.5g/cm3 and the soda bottles were only 1.4g/cm3. This tells us that the concentrated sugar water is denser than the soda bottles, thus making the soda bottle powder float.
 * ~ Object ||~ Material ||~ Mass (g) ||~ Volume (cm 3 ) ||~ Density (g/cm 3 ) ||
 * Wooden desk || wood ||  ||   ||   ||
 * Key || steel ||  ||   ||   ||
 * Chopping board || wood ||  ||   ||   ||
 * Fishing weight || lead ||  ||   ||   ||
 * Club hammer || steel ||  ||   ||   ||
 * Floor tile || marble ||  ||   ||   ||
 * Safety glasses || perspex ||  ||   ||   ||

As water has a density of 1g/cm3, the milk jugs, with a lesser density of 0.95g/cm3, will float to the top while the soda bottles and aluminum soda cans, with heavier densities of 1.4g/cm3 and 2.7g/cm3, will sink to the bottom.

A soda bottle which has a density of 1.4g/cm3 will float whereas a aluminum soda can which has a density of 2.7g/cm3 will sink.

The density of ice is__ less __ dense than the density of water because the amount of__ mass __ in solid water/ice is__ small er__ than the amount of mass in liquid water for the unit __ volume __.

[|Density game] from www.mangahigh.com

Floating rocks
A rock ususlly sinks in water as the density of a normal rock is __ greater __ than the density of water( __ 1 __g/cm3). Oil is __ less __ dense than water so it floats in water. From our experiment, the mass of water was 30g while the mass of oil was __ 27 __g for the same volume(30ml) of water. If the volume of the rock is 30ml, the mass of the rock should be __ greater __ than 30g but the floating rock has smaller mass than 30g as there are a lot of __ holes __ in it.

media type="youtube" key="UukRgqzk-KE" width="560" height="315" [|Why does ice float in water] from TED-ED youtube.com George Zaidan and Charles Morton [|TED-Ed] Published on 22 Oct 2013
 * Why does ice float in water? **

Explain that pressure is caused by the action of a force on an area. P= Force / Area
 * Pressure in liquids and gases **

Explain pressures in gases and liquids (qualitative only). Investigate the pressure due to a solid Investigate the vacuum flask