Question

The diameter of circular base of a cylinder is 7 metres. If volume is 770cu.m.Then find its height and total surface area?​

Answer 1

Given:

• Diameter of base of cylinder = 7m
• Volume = 770 m³

To find :

• Height
• TSA

Formula used :

• Volume of cylinder = πr²h
• TSA = 2πr(r+h)

Solution :

• Let - Height = h
• Radius = Diameter ÷ 2 = 7m/2 = 3.5m

$\sf \implies \: Volume \: = \pi \: {r}^{2} h \\ \\ \sf \implies \:770 = \dfrac{22}{7} \times {(3.5)}^{2} \times h \\ \\ \sf \implies \:h \: = \: \dfrac{770 \times 7}{22 \times 3.5 \times 3.5} \\ \\ \sf \implies \:h \: = \dfrac{5390}{269.5} \\ \\ \sf \implies \:h \: = 20m$

Therefore height = 20 m

Now TSA = 2πr(r+h)

$\sf \implies \: TSA \: = \: 2 \times \dfrac{22}{7} \times 3.5 \times ( 3.5 + 20) \\ \\ \sf \implies \: TSA \: = \: \dfrac{22}{7} \times 7 \times (23.5) \\ \\ \sf \implies \: TSA \: = \: 22 \times 23.5 \\ \\ \sf \implies \: TSA \: = \: 517 {m}^{2}$

ANSWER :

• Height = 20m
• TSA = 517 m²

Answer 2

☯ Answer ☯

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• Height of cylinder is 20 m${\boxed{\green{\checkmark{}}}}$.

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• Total surface area of cylinder is 517 m².${\boxed{\red{\checkmark{}}}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

$\large\underline{\red{\sf \orange{\bigstar} Given:-}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• The Diameter of base of cylinder is 7 m.

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• Volume of cylinder of 770 m³.

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

$\large\underline{\pink{\sf \red{\bigstar} To Find:-}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• Height of cylinder.

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• Total surface area of cylinder.

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

$\large\underline{\blue{\sf \orange{\bigstar} Solution:-}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• Radius = Diameter/2

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• $\longrightarrow$ Radius = 7/2

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• $\longrightarrow$ Radius = 3.5

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

Volume of cylinder = πr²h

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

☢ Where ☢

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• r is radius of cylinder.

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• h is height of cylinder.

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

☮ Put values ☮

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• $\longrightarrow$ 770 = πr²h

• $\longrightarrow$ 770 = 22/7 × (3.5)² × h

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• $\longrightarrow$ 770 = 22/7 × 12.25 × h

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• $\longrightarrow$ 770 × 7 = 269.5 × h

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• $\longrightarrow$ 5390 = 269.5 × h

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• $\longrightarrow$ 5390/269.5 × h

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• $\longrightarrow$ h = 20

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

Thus,⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

☯ Height of cylinder is 20 m. ☯

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

$\large\underline{\purple{\sf \orange{\bigstar} Now:-}}$

We know,

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

$\pink{\sf{\star\;Total \;surface \;area \;of \;cylinder \;=\; 2πr² \;+ \;2πrh}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• $\longrightarrow$ 2 × 22/7 × (3.5)² + 2 × 22/7 × 3.5 × 20

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• $\longrightarrow$ 44/7 × 12.25 + 44/7 × 70

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• $\longrightarrow$ 539/7 + 3080/7

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• $\longrightarrow$ 77 + 440

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

• $\longrightarrow$ 517

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

Therefore,

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

$\green{\sf{\star\;Total\; surface\; area \;of \;cylinder\; is \;517 m².}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀