Answer:
314 ft²
Step-by-step explanation:
Data provided in the question:
Depth (height) of the pool = of its radius
let the radius be 'r' ft
thus,
Depth (height) of the pool, h = ft
Volume of the pool = 1570 ft³
also,
Volume of cylinder = πr²h
thus,
1570 ft³ = πr²h
or
1570 ft³ =
or
3140 = 3.14 × r³ [ π = 3.14 ]
or
r³ = 1000 ft³
or
r = 10 ft
Thus,
Area of the bottom surface = πr²
= 3.14 × 10²
= 314 ft²
Answer:
Step-by-step explanation:
Since, we know that,
The surface area of a cylinder having both ends in both sides,
Where,
r = radius,
h = height,
Given,
Diameter of the sphere = 4 cm,
So, by using Pythagoras theorem,
( see in the below diagram ),
Thus, the surface area of the cylinder,
Differentiating with respect to r,
Again differentiating with respect to r,
For maximum or minimum,
Since, for r = √2,
Hence, the surface area is maximum if r = √2,
And, maximum surface area,
