Area, Volume, Density & Flotation (Notes)

Area

• The area of a shape is the amount of surface enclosed within it’s boundary lines.

• m2 or cm2

• Area of a rectangle or square = length x width

• Area of a disc = ∏ x r x r

• Area of a triangle = ½ x base x perpendicular height

Volume

• The volume of the object is the amount of space it takes up.

• m3 or cm3

• Graduated cylinder / burette / pipette (liquids)

• Length x width x depth (regular solid)

• Overflow can (irregular solid)

Density

• The density of a substance is its mass per unit volume.

• Electronic balance / Graduated cylinder & electronic balance.

• Density = Mass / Volume

• kgm−3 or cmg−3

Flotation

• An object floats in a liquid if its density is less than the density of the liquid.

• An object sinks in a liquid if its density is greater than the density of the liquid.