Density

Volume The volume of an object is the amount of space it takes up The SI unit of volume is the cubic metre (m 3 ) or cubic centimetre (cm 3 ). The Litre is also used (1L = 1000cm 3 )

Graduated Cylinders, burettes, & pipettes are used to measure the volume of a liquid Measuring the Volume of a Liquid Burette Pipette Graduated Cylinders

The volume of a liquid is read from the lowest part of the Meniscus (curve) Measuring the Volume of a Liquid

The volume of regular solids e.g. cubes, can be found by simply measuring their length, width, & height and using the formula Measuring the Volume of a Solid Volume = Length x Width x Height

Remember……. 1m 3 = 1m x 1m x 1m 1m 3 = 100cm x 100cm x 100cm 1m 3 = 1,000,000 cm 3

Measuring the Volume of a Solid A displacement can and a graduated cylinder is used to find the volume of a solid with an irregular shape

Mass The mass of an object is the amount of matter in it

Density The density of a substance is its mass per unit volume Density = Mass/Volume

Density = Mass Volume D = M/V M D V Measured in kilograms per metre cubed (kg/m 3 ) Also g/cm 3 Density

DENSITY Mandatory Experiment

Density of a Solid Rectangular Block

Desity of a irregular Solid

Density of a Liquid

What is Density? Density is the Mass per unit Volume WoodWaterIron 1 cm 3 1 cm 3 1 cm 3 If you take the same volume of different substances, then they can have different masses 0.50 g1.00 g8.00 g Q) Which has the greatest mass and therefore the most dense? IRON

DENSITY OF A REGULAR SOLID Find the Mass of the solid on a balance. Measure the three lengths and calculate the Volume. (ie V = l x w x h ) Calculate the Density. 4.0 cm 2.0 cm 3.0 cm  = m = 240 =10.0 g/cm 3 V 24 m = 240 g

MaterialMass in g Length in cm Width Height Volume in cm 3 Density in g/cm 3

DENSITY g/cm 3 Aluminium2.70 Brass8.50 Iron7.86 Wood0.50 Slate2.80 Glass2.50 Lead11.3 Marble2.70 Wax0.89

DENSITY OF AN IRREGULAR SOLID Find the Mass of the solid on a balance. Find the Mass of the solid on a balance. Fill the Measuring Cylinder with Water to a known Volume. Fill the Measuring Cylinder with Water to a known Volume. Add the Object. Add the Object. Work out the Volume of Water that is displaced. Work out the Volume of Water that is displaced. Calculate the Density. Calculate the Density. 50 cm 3 80 cm 3 m = 360 g  = m = 360 =12.0 g/cm 3 V 30

DENSITY OF AN IRREGULAR SOLID OR use a Eureka Can to find the Volume. Find the mass of the solid on a balance. Find the mass of the solid on a balance. Add water until just overflowing. Add water until just overflowing. Place a Measuring Cylinder under the spout. Place a Measuring Cylinder under the spout. Add the Object. Add the Object. Collect the Water and read off the Volume. Collect the Water and read off the Volume. Calculate Density Calculate Density m = 440 g 40.0 cm 3  = m = 440 =11.0 g/cm3 V 40

DENSITY g/cm 3 Aluminium2.70 Iron7.86 Brass8.50 Wood0.50 Slate2.90 Glass2.50

DENSITY OF A LIQUID Find the Mass of an empty Measuring Cylinder. Add a certain Volume of Liquid. Find the Mass of the Measuring Cylinder and Liquid Calculate the Mass of Liquid. How? Calculate Density of Liquid. Mass of Liquid = Mass of Measuring Cylinder and Liquid – Mass of empty Measuring Cylinder 25.0 g 20.0 cm g 45 – 25 = 20 g  = m = 20 =1.00 g/cm3 V 20

Liquid Mass of empty Measuring Cylinder in g Mass of Measuring Cylinder and Liquid in g Mass of Liquid in g Volume in cm 3 Density in g/cm 3

DENSITY OF A GAS Remove the air from a flask of a known Volume, using a vacuum pump. Find its Mass. Add the gas to be tested. Reweigh. The difference is the Mass of gas. Calculate Density. To vacuum flask 1000 cm g g  = m = 20 = g/cm3 V = 20.0g

Flotation

An object will float if it is less dense than the liquid An object will sink if it is more dense than the liquid One liquid can float on top of another e.g oil floats on water

Density is the amount of mass in a particular volume Density = g/ cm 3 Mass (g) Volume (cm 3 ) A B Diagram B shows a greater density than diagram A because there is more mass in the same volume. If a substance is more dense than water then it will sink If a substance is less dense than water then it will float

Dancing Raisins 4o 4o

Experiment with the coke and diet coke GJ48 GJ48 Mythbusters Us Us

Your Task Design an experiment that effects the density of your object. You have to make objects float that usually sink Remember salt has particles!.

Can I Make an object Sink? If an object originally floats can I make it sink? vU_o&feature=related

Homework Workbook Pg 134 Q Workbook Pg 135 Q 9 10

Q Why does one balloon float and the other Sinks?

Explain why this man floats in the dead sea?

Homework Pg 248 of text book Q 1,2,4,6,7,8

Density Experiment