Question

Find the lateral curved surface area of a cylinder petrol storage tank that is 4.2m in diameter and 4.5m in height. How much steel was actually used, if 1/12 of the steel actually used was wasted in making the closed tank?​

Answer 1

Answer:

59.4

Step-by-step explanation:

lateral surface area of cylinder=2πr

2×22/7×2.1×4.5

44/7×2.1×4.5

415.8/7

59.4

Answer 2

Given :-

Diameter of petrol storage tank is 4.2m

Height of petrol storage tank is 4.5 m

Solution 1 :-

Here,

Diameter = 4.2

Radius = Diameter / 2 = 4.2/2 = 2.1

Height = 4.5m

Now,

Curved surface area of cylindrical = 2πrh

Put the values in the formula ,

CSA of petrol storage tank = 2 * 22/7 * 2.1 * 4.5

CSA of petrol storage tank = 2 * 22 * 0.3 * 4.5

CSA of petrol storage tank = 59.4 m^2

Solution 2 :-

Here, We have to find that how much steel is actually if 1/12 of the steel actually used was wasted in making the closed tank.

Here,

Height = 4.5m

Radius = 2.1

Now,

TSA of cylinder = 2πr( r + h)

Put the required values,

TSA of petrol storage tank

= 2 * 22/7 * 2.1 ( 2.1 + 4.2 )

= 2 * 22 * 0.3 * 6.3

= 87.12 m^3

Now,

Let the total amount of steel used in making tank be x

It is given that,

1/12 steel is wasted

According to the question,

Amount of steel required - wasted steel = TSA of tank

Put the required values,

x - x/12 = 87.12

11/12x = 87.12

x = 87.12

x = 95.04 m^2

Hence, 95.04m^2 Steel is used to make the tank $.$