Mass and Density
What is mass?
a property of an object related to the amount of matter it has. Mass is related to inertia (the state of rest or movement).
An object has the same mass if it is in space or on Earth. BUT it does not have the same WEIGHT in space vs on Earth
What is density?
the relationship between a substance's mass and its volume
What is volume?
the space that a physical body occupies
what units would you use to measure the length of the classroom?
kilometers, centimeters, meters?
meters or centimeters
convert the distance 0.75 km to m
750 m
kg
what is the SI (standard) unit for density?
kg/m3
What is the SI unit for volume?
cubic meters (m3) equivalent to a cube with 1 m on all sides
what units would you use to measure how much a person weighs?
micrograms, femtograms, kilograms, grams?
kilograms
convert the distance 0.75 km to Gm (gigameters)
7.5 x 10-7 Gm
a group of students weighed pieces of iron in the laboratory, express the following in grams:
10 g
29 kg
12 hg
7 Gg
b) 2.9 x 104 g
c) 1.2 x 103 g
d) 7 x 109 g
What is the density of a material if its mass is 30 kg and its volume is 5 cubic meters?
4 kg/m3
a) convert 7 cm3 to m3
b) convert 10 cm3 to m3
c) convert 140 cm3 to m3
a) 7 x 10-6 m3
b) 1 x 10-5 m3
c) 1.4 x 10-4 m3
what is the SI unit for time?
seconds (s)
7.5 x 105 mm
What is the density of Glass?
Mass = 183.7 grams
Volume = 73.5 cm3
2.49 g/cm3
2.49 × 103 kg/m3
use the following data to calculate the density of sand:
mass of graduated cylinder with water: 193.8 g
volume of the water in the graduated cylinder: 62 cm3
mass of the graduated cylinder with water and with sand: 275.4 g
volume of the water with the sand 93 cm3
81.6 g mass of the sand
31 cm3 volume of the sand
d= m/v so density of the sand is 2.63 g/cm3
the SI unit of density is kg/m3 so it becomes 2.63 x103 kg/m3 when we convert
the density of water is 1 g/cm3
1000 kg/m3 x 12 = 12,000 kg/m3
1.2 x 104 kg/m3
what is the SI unit for length?
meters (m)
convert 0.75 km to micrometers (um)
7.5 x 108 um
What is the density of Lead in kg/m3?
mass: 329 g
volume: 125 cm3
2.632 x 103 kg/cm3
The king asked Archimedes if his crown was only made of gold. First archimedes calculated the density of gold by weighing 1000 g of gold and measuring its volume 53 cm3 next he measured the volume of the crown which was 37.5cm3 the crown weighed 500g. Is it pure gold?
no
we pour water into a graduated cylinder until we reach the signal for 700 cm3 next we introduce a stone and the water level rises to 950 cm3 . what is the volume of the stone?
2.5 x 10-4 m3
what is the SI unit for temperature?
Kelvins (K)
convert 0.75 km to Mm (megameters)
7.5 x 10-4 Mm