Find
(1) The total surface area of a closed cylindrical petrol storage tank whose diameter
4.2 m. and height 4.5 m.
2)How much steel sheet was actually used, if 1/12
of the steel was wasted in making
the tank
Answers
Answer:
Step-by-step explanation:
Given :-
Radius of the tank (r) = 4.2/2 m = 2.1 m
Height of the tank (h) = 4.5 m
To Find :-
Total Surface Area
Formula to be used :-
Curved surface area = 2πrh
Total surface area of the tank = 2πr(r + h)
Solution :-
Putting all the values, we get
⇒ Curved surface area = 2πrh
⇒ Curved surface area = (2 × 22/7 × 2.1 × 4.5)
⇒ Curved surface area = 59.4 m²
⇒ Total surface area of the tank = 2πr(r + h)
⇒ Total surface area of the tank = [2 × 22/7 × 2.1 (2.1 + 4.5)]
⇒ Total surface area of the tank = 87.12 m²
Number 2.
Given :-
1/12 of the steel was wasted in making the tank.
To Find :-
Steel Required
Solution :-
Let x be the actual steel used in making tank.
⇒ (1 - 1/12) × x = 87.12
⇒ x = 87.12 × 12/11
⇒ x = 95.04 m²
Hence, 95.04 m² of steel required.
1) The total surface area of a closed cylindrical petrol storage tank whose diameter 4.2 m and height 4.5 m.
AnswEr :
- Height ( h ) = 4.5 m
- Radius ( r ) = Diameter / 2 = 4.2 / 2 = 2.1 m
- Total Surface Area of Cylindrical Tank.
⇒ T.S.A. of Cylinder = 2πr( r + h )
- Plugging the Values
⇒ T.S.A. of Cylinder = 2 × 22 /7 × 2.1 m(2.1 m + 4.5 m)
⇒ T.S.A. of Cylinder = 2 × 22 × 0.3 × 6.6
⇒ T.S.A. of Cylinder = 44 × 1.98
⇒ T.S.A. of Cylinder = 87.12 m²
჻ Total Surface Area of Tank is 87.12 m²
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2) How much steel sheet was actually used, if 1/12 of the steel was wasted in making the tank.
AnswEr :
Let the steel sheet used in making of tank be x metre.
- wasted steel = 1 / 12 of Total = x / 12
• According to Question Now ;
⇒ Total Sheet - Wasted Sheet = T.S.A.
- Plugging the Values
⇒ ( x ) - ( x / 12 ) = 87.12 m²
⇒ ( 12x - x ) / 12 = 87.12 m²
⇒ 11x / 12 = 87.12 m²
⇒ x = ( 87.12 m² × 12 ) / 11
⇒ x = ( 7.92 m² × 12 )
⇒ x = 95.04 m²
჻ Total Steel Sheet used was 95.04 m²