Ant. / Ans. 1.1
BO / SA = 2lb + 2(l + b)h
= 2 x 4 x 8 + 2(4 + 8) x 5 cm
2
= 64 + 120 cm
2
= 184 cm
2
Vol = lbh
= 4 x 8 x 5 cm
3
= 160 cm
3
Vr. / Qu. 1.1
Ant. / Ans. 1.2
BO / SA = 2πr
2 + 2πrh
= 2 x π x 11
2 + 2 x π x 11 x 12 mm
2
= 760,2654 + 829,3804 mm
2
= 1 589,65 mm
2
Vol = πr
2h
= π x 11
2 x 12 mm
3
= 4 561,59 mm
3
Vr. / Qu. 1.2
Ant. / Ans. 1.4
BO / SA = 2πr
2 + 2πrh
= 2 x π x 21
2 + 2 x π x 21 x 14 cm
2
= 2 770,88472.. + 1 847,25648.. cm
2
= 4 618,14 cm
2
Vol = πr
2h
= π x 21
2 x 14 cm
3
= 19 396,19 cm
3
Vr. / Qu. 1.4
Ant. / Ans. 1.5
BO prisma = 2 x opperv. driehoek + omtrek x lengte van prisma
= bh + (s1 + s2 + s3)l
Vol = opperv. van driehoekige basis x lengte = (1/2)bhl
Ant. / Ans. 1.5
SA prism = 2 x area of triangle + perimeter of triangle x length
= bh + (s1 + s2 + s3)l
Vol = area of triangular base x length = (1/2)bhl
BO prisma / SA prism = bh + (s1 + s2 + s3)l
= 24 x 12 + (18 + 18 + 24) x 20 cm2
= 288 + 1 200 cm2
= 1 488 cm2
Vol = (1/2)bhl
= (1/2) x 24 x 12 x 20
3 cm
3
= 2 880 cm
3
Vr. / Qu. 1.5
2.1
nuwe mates / new measurements: l = 16 cm, b = 8 cm,
h = 10 cm
BO / SA = 2bh + 2(b + h)l
= 2 x 8 x 10 + 2(8 + 10) x 16 cm2
= 736 cm2
Vol = lbh
= 16 x 8 x 10 cm3
= 1 280 cm3
2.2
Ou BO / Original SA = 184 cm2 en / and
Nuwe BO / New SA = 736 cm2.
Verandering / Change = 736 ÷ 184 = 4
Ou / Original Volume = 160 cm3 en / and
Nuwe / New Volume = 1 280 cm3.
Verandering / Change = 1 280 ÷ 116 = 8
3.1
BO kubus / SA cube = 6s2
6s2 = 150
s = √(150 ÷ 6)
= 5
sy / side = 5 cm
3.2
Vol kubus / cube = s3
= 53 cm3
= 125 cm3
4.1
Volume silinder / cylinder = πr2h
πr2 x 18 = 1 413
r = √(1 413 ÷ 18 × π)
= 5
radius = 5 mm en / and
middellyn / diamter is 10 mm.
4.2
BO silinder/SA cylinder = 2πr2 + 2πrh
= 2 x π x 52 + 2 x π x 5 x 18 mm2
= 722,57 mm2
BO / SA = 4πr2
= 4 x π x 52 cm2
= 314,16 cm2
OF / OR
BO / SA = 4π(d ÷ 2)2
= πd2
= π102 cm2
= 314,16 cm2
Volume = (4 ÷ 3)πr3
= (4/3) x π x 53 cm3
= 523,60 cm3
6.1
BO / SA = πr2 + πrh
= π x 62 + π x 6 x 30 cm2
= 678,58 cm2
6.2
Volume = (1 ÷ 3)πr2h
= (1/3) x π x 62 x 8 cm3
= 301,59 cm3
7.1
BO / SA = 4πr2
∴ 4 x π x r2 = 1 257
r2 = 1 257 ÷ 4 π
= 100
r = 10 dm
7.2
Volume = (4 ÷ 3)πr3
= (4/3) x π x 103 dm3
= 4 188,79 dm3
8.1
BO / SA = πr2 + πrh
= π x 62 + π x 6 x 15 mm2
= 395,84 mm2
6.2
Volume = (1 ÷ 3)πr2h
= (1/3) x π x 62 x 9 mm3
= 339,29 mm3
Volume van keël /
Volume of cone = (1/3) x πr2 x h
= (1/3) x π x (6/2)2 x 6 cm3
= 56,55 cm3
Volume roomys /
ice cream = (4 ÷ 3)πr3
= (4/3) x π x 33 cm3
= 113,10 cm3
Die volume van die roomys is dubbel die kapasiteit van die horing en kan dus nie in die
horing inpas nie.
The volume of the ice crean is double the capacity of the cone and cannot be contained in the cone.
Vraag / Question 9
volume |
|
volume |
|
8 |
──────────── |
= |
──────────── |
= |
─── |
buite-oppervlakte |
|
surface area |
|
3 |
∴
3 × Volume = 8 × BO / SA
3 × (4 ÷ 3) × π × r3 = 8 × 4 × π × r3
4 × π × r3 = 32 × π × r3
r = 8 . . . ÷ met / by 4 × π × r2
BO / SA = 4 x π x r2
= 4 x π x 82
= 804,25 eenhede/units2
Volume = (4 ÷ 3) x π x r3
= (4/3) x π x 83
= 2 144,66 eenhede/units3
lengte van bak = lengte van plaat − 2 x breedte van omgevoude stuk
= 150 − 2 x 5 = 140 cm
breedte van bak = breedte van plaat − 2 x breedte van omgevoude stuk
= 65 − 2 x 5 = 55 cm
length of basin = length of sheet − 2 x width of upturned piece
= 150 − 2 x 5 = 140 cm
breadth of basin = breadth of sheet − 2 x breadth of upturned piece
= 65 − 2 x 5 = 55 cm
volume = lbh
= 140 x 55 x 5 cm3
= 38 500 cm3
= 38 500 ÷ 1 000 l . . . 1 000 cm3 = 1 l
= 38,5 l
r = 1,5 ÷ 2 = 0,75
|
1 |
|
4 |
|
1 |
|
Volume = |
── |
( |
── |
π r3) + π r2 h + |
─ |
π r2 h |
|
2 |
|
3 |
|
3 |
|
|
|
|
2 |
|
1 |
|
|
|
= |
── |
× π 0,753 + π × 0,752 × 2 + |
─ |
× π × 0,752 × 0,25 m3 |
|
|
|
3 |
|
3 |
|
= 4,565 m
3
Oppervlakte halwe sfeer / Area of half a sphere = (1/2) x 4 π r
2 = 2 π r
2
= 2 × π × 0,75
2 m
2
= 3,53429... m
2
Oppervlakte silinder / Area of cylinder = 4 π r h
= 2 × π × 0,75 × 2 m
2
= 9,42477... m
2
Oppervlakte keël / Area of cone = π r skuinshoogte / slanting height
= π × 0,75 × 0,79 m
2
= 1,86139... m
2
Totale buite-oppervlakte / Total surface area = 3,53429 + 9,42477 + 1,86139 m
2
= 14,82 m
2
Vraag / Question 12