Two cylinders are covered with papers on the curved surfaces. The top and bottom regions of the cylinder are left exposed. If the length of the papers just covers the surface area of the cylinder (after cutting them if necessary), then what is the sum of the volumes of the two cylinders in cc? The height of the 1st cylinder and 2nd cylinder is 10cms and 12cms respectively. The area of the paper covering the first cylinder is 10cm * 8cm and the second is 10cm * 4cm. The answers are to be correct to two decimal places.
Answers
Answer:
61.54
Step-by-step explanation:
1 cylinder =2*π*r1*10=10*8
2 cylinder=2*π*r2*12=10*4
r1=10*8/2*π*10
=4/π
r2=10*4/2*π*12
=5/3π
volume of two cylinder =π*r1^2*h+π*r2^2*h
22/7*4^2*7/22*7/22*10+22/7*5^2/3^2*7/22*7/22*12
ans=6.15
Answer:
61.57 cm²
Step-by-step explanation:
The height of the 1st cylinder = 10 cm
The area of the paper covering the first cylinder is 10cm * 8cm = 80 cm²
Curved Surface Area of cylinder = 2πr₁h₁ = 2πr*10
2πr*10 = 80
=> πr = 4 cm
The height of the 2nd cylinder = 12 cm
The area of the paper covering the first cylinder is 10cm * 4cm = 40 cm²
Curved Surface Area of cylinder = 2πr₂h₂ = 2πr*12
2πr₂*12 = 40
=> πr₂ = 5/3 cm
Volume of cylinder = πr²h
Sum of Volume of cylinder = πr₁²h₁ + πr₂²h₂
= (4²/π ) * 10 + (5²/3²π ) * 12
= 160/π + 100/3π
= (580)/3π
= 61.57 cm² (using π = 3.14)