Page 67 # 1-5 (blue book) density
1(a) If the density of wood is 0.5g/cm3, what is the mass of
1 cm3
(i)
(ii) 2 cm3
M= ? g
D= 0.5g/cm
(6)
(iii) 10cm3
M= ? g
3
M= ? g
D= 0.5g/cm
3
D=0.5g/cm
V= 1cm3
V=2cm3
V= 10cm3
D= M/V
D= M/V
D= M/V
M= D X V
M= D X V
M= D X V
M = 0.5g/cm3 X 1cm3
M= 0.5 g/cm3 X 2cm3
M= 0.5 g
M= 1.0 g
M= 5g
(ii)
volume 3 m3 and mass 9kg
D=?
D=?
M= 100g
M= 9kg
V = 10cm3
V = 3m3
D=M/V
D=M/V
D= 100g/ 10cm3
D= 9kg/3m3
D= 10g/cm3
D = 3kg/m3
1(c) The density of gold is 19g/cm3. Find the volume of
(i)
38g of gold
Write base equation
and rearrange if
necessary
M = 0.5g/cm3 X 10cm3
1(b) What is the density of a substance of: (4)
(i) mass 100g and volume 10cm3
Pick out info Write
info along with
units
3
(4)
(ii) 95g of gold
D= 19g/cm3
D= 19g/cm3
M= 38g
M = 95 g
D=M/V
D=M/V
V=M/D
V=M/D
V= 38g / 19g/cm3
V= 95g / 19g/cm3
V= 2 cm3
V=5 cm3
Substitute values
along with the
units. Work out
units of the answer
Calculate, write answer
with the correct unit
2. A piece of steel has a volume of 12cm3 and a mass of 96g. What is its density in:
(a) g/cm3
(4)
(b) kg/m3
V= 12 cm3
Convert
units
M=96g
D=M/V
V = 12cm3 = 12/(100X100X100) = 0.000012m3
M = 96g = 0.096kg
D=M/V
Substitute along with the units
D= 96g / 12cm3
D= 8g/cm3
D= 0.096Kg / 0.000012m3
D= 8000 kg/m3
3. What is the mass of 5m3 of cement of density 3000kg/m3? (2)
M= ?
V= 5m3
D=M/V
M= DX V
D= 3 000kg/m3
M= 3 000kg/m3 X 5m3
M = 15 000kg
4. What is the mass of air in a room measuring 10m X 5.0m X 2.0m if the density of air is 1.3kg/m 3? (2)
M=?
V= 10m X 5.0m X 2.0m = 100m3
D=M/V
M= DXV
M= 1.3kg/m3 X 100m3
D= 1.3kg/m3
M= 130kg
5. A Perspex box has a10cm square base and contains water up to a height of 10cm. A piece of rock of mass 600g is
lowered into the water and the level rises to 12 cm.
12cm
10cm
10cm
10cm
10cm
10cm
(a) What is the volume of water displaced by the rock? (2)
Volume of water in box= L X W X H
(Square base means 10cm X 10cm for the bottom of the box)
V= 10cm X10cm X 10cm = 1000cm3
Volume of water and rock = 10cm X 10cm X 12 cm = 1200cm3
Volume of rock = 1200cm3 – 1000cm3 = 200cm3 (this is the volume of the water displaced by the rock.)
(b) What is the volume of the rock? V= 200cm3
(2)
(c) What is the density of the rock?
(2)
3
M= 600g
V = 200cm
D= M/V
D = 600g / 200cm3 = 3g/cm3
Total marks 28