Answer:
122.7792 sq. m
Step-by-step explanation:
diameter= 8.4 m
therefore, radius = r = 4.2 m.......( as radius is 1/2 of diameter)
height = h= 12 m
only the exterior is to painted so the total surface area of the cylinder is taken,
total surface area of cylinder = 2π r( h+r)
=2* 3.14* 4.2*(12+4.2)
=122.7792 sq. m
Volume of cylinder:
V = πr²h
The desired volume is 1 Liter = 1000 cm³
1000 = πr²h
h = 1000/πr²
Surface area of cylinder:
S.A = 2πr² + 2πr²h
We substitute the value of h from the first equation:
S.A = 2πr² + 2πr(1/πr²)
S.A = 2πr² + 2/r
Now, to minimize surface area, we differentiate the expression with respect to r and equate to 0.
0 = 4πr - 1000/r²
4πr³ - 1000 = 0
r = 4.3 cm
h = 17.2 cm
-8/5 is the correct answer
Answer:
Ethan
Question b is incomplete
Step-by-step explanation:
Given the masses of the 6 insects below :
Name of Insect ______ Mass (m)
Arthur _____________ 7.8259
Bethan ____________ 7.2659
Clarry ______________8.159
Deena _____________ 7.4559
Ethan ______________ 8.9459
Freya ______________ 7.0159
Write the name of the stick insect with m > 8.85g
Mass (m) greater than 8.55 g
From the table :
8.945 > 8.55 ;
Hence, Ethan
(b) Write the name of the stick insect with m s 7.155 g
Question b isn't complete
