Question

the curved surface area of a right circular cylinder is 4.4cm2 if the radius of the base of the cylinder is 0.7m find its height and also find the cost of painting it's total surface area at rs.5per sq.m​

Answer 1

Answer:

Explanation:

Given :

• CSA of a right circular cylinder = 4.4 cm² → 0.0044 m²
• Radius (r) = 0.7 m

To Find :

• It's height & cost of painting.

Solution :

CSA of a right circular cylinder = 2πrh

→ 0.0044 = 2 × 22/7 × 0.7 × h

→ 0.0044 = 44 × 0.1 × h

→ 0.0044 = 4.4 × h

→ h = 0.0044/4.4

→ h = 0.0001 m

We know,

TSA of a right circular cylinder = 2πr(r + h)

→ TSA = 2 × 22/7 × 0.7 (0.7 + 0.0001)

→ TSA = 44 × 0.1 (0.7001)

→ TSA = 3.08044 m²

So,

Cost of painting = TSA × Rate

→ Cost = 3.08044 × 5

→ Cost = Rs. 15.4022

Hence :

It's height & cost of painting is 0.001 m and Rs. 15.4022 respectively.

Answer 2

$\Large \rm{ \underline {\blue{Giѵҽղ : }}}$

• Radius = 0.7m
• CSA of a right circular cylinder = 4.4 cm² ➼ 0.0044 m²

$\Large \rm{ \underline{ \purple{Tᴏ \: Fɪɴᴅ : }}}$

• Height of the painting
• Cost of the painting

$\Large \rm{ \underline{ \green{ѕοlutiοn : }}}$

CSA of a right circular cylinder = 2πrh

➠ 0.0044 = 2 × 22/7 × 0.7 × h

➠ 0.0044 = 44 × 0.1 × h

➠ 0.0044 = 4.4 × h

➠ h = 0.0044/4.4

➠ h = 0.0001 m

We know,

TSA of a right circular cylinder = 2πr(r + h)

➠ TSA = 2 x 22/7 × 0.7 (0.7 + 0.0001)

➠ TSA = 44 × 0.1 (0.7001)

➠ TSA = 3.08044 m²

So, Cost of painting = TSA × Rate

➠ Cost = 3.08044 × 5

➠ Cost = Rs. 15.4022

Hence, the height of painting is 3.08044 m² the cost of painting is Rs. 15.4022² respectively.