Tolong di kerjakan menggunakan cara!

Tolong di kerjakan menggunakan cara!

Jawaban:

Rumus Volume Tabung

$V = frac{1}{3} times pi times {r}^{2} times t$

keterangan:

V = volume kerucut

t = tinggi kerucut

r = panjang jari jari alas kerucut

phi = 22/7 atau 3,14

jika phi habis dibagi 7 gunakan 22/7 dan sebaliknya

1. a. r = 7 dan t = 20

$V = frac{1}{3} times pi times {r}^{2} times t \ = frac{1}{3} times frac{22}{7} times {7}^{2} times 20 \ = frac{1}{3} times 154 times 20 \ = frac{1}{3} times 3.020 \ = 1.026,7 {cm}^{3}$

b. r = 5 dan t = 12

$V = frac{1}{3} times pi times {r}^{2} times t \ = frac{1}{3} times3,14 times {5}^{2} times 12\ = frac{1}{3} times 78,5 times 12 \ = frac{1}{3} times 942 \ = 314 {cm}^{3}$

c. r= 10 dan t = 18

$V = frac{1}{3} times pi times {r}^{2} times t \ = frac{1}{3} times3,14 times {10}^{2} times 18\ = frac{1}{3} times314 times 18 \ = frac{1}{3} times 5.652 \ =1.884 {cm}^{3}$

d. r = 15 dan t = 20

$V = frac{1}{3} times pi times {r}^{2} times t \ = frac{1}{3} times3,14 times {55}^{2} times 20\ = frac{1}{3} times 706,5 times 20 \ = frac{1}{3} times 14.130 \ =4.710 {cm}^{3}$

e. r = 10,5 dan t = 24

$V = frac{1}{3} times pi times {r}^{2} times t \ = frac{1}{3} times3,14 times {10,5}^{2} times 24\ = frac{1}{3} times 346,185times24 \ = frac{1}{3} times8.308,44\ =2.769,48 {cm}^{3}$

f. r = 14 dan t = 21

$V = frac{1}{3} times pi times {r}^{2} times t \ = frac{1}{3} times frac{22}{7} times {14}^{2} times 21 \ = frac{1}{3} times 154 times 21 \ = frac{1}{3} times 3.234 \ = 1.078 {cm}^{3}$

$2)V = frac{1}{3} times pi times {r}^{2} times t \ = frac{1}{3} times frac{22}{7} times {21}^{2} times 30 \ = frac{1}{3} times 1.386 times 30 \ = frac{1}{3} times 41.580 \ = 13.860 {cm}^{3}$

$3)V = frac{1}{3} times pi times {r}^{2} times t \ = frac{1}{3} times frac{22}{7} times {7}^{2} times 27 \ = frac{1}{3} times 154 times 27 \ = frac{1}{3} times 4.158 \ = 1.386 {cm}^{3} \ = frac{2}{3} times 1.386 \ = frac{2.272}{3} \ = 924 {cm}^{3}$

$4)r = frac{ sqrt{3 times : V } }{pi times t} \ r = frac{ sqrt{3 times 16.632} }{ frac{22}{7} times 36 } \ r = frac{ sqrt{49.896} }{ frac{792}{7} } \ r = frac{7 times 49.896}{792} \ r = frac{ sqrt{349.272} }{792} \ r = sqrt{441} \ r = 21 : cm$

5. V.tabung di luar kerucut

caranya V.tabung – V kerucut

$(pi times {r}^{2} times t) - ( frac{1}{3} times pi times {r}^{2} times t)\ = (frac{22}{7} times{7}^{2}times 30) - ( frac{1}{3}timesfrac{22}{7}times{7}^{2}times30\ = (154 times 30) - ( frac{1}{3} times 154 times 30) \ = 4.620 - frac{1}{3} times 4.620 \ = 4.620 - 1.540 = 3.080 {cm}^{3}$