A right circular cylindrical metallic rod is 15 inches tall. The radius of the base is 2 inches. What is the surface area of the metallic rod in terms of pie?

Surface area = 68π inches²

Step-by-step explanation:

The formula for determining the total surface area of the circular cylindrical metallic rod is expressed as

Total surface area = 2πr² + 2πrh

Where

r represents the radius of the cylindrical rod.

h represents the height of the cylindrical rod.

π is a constant whose value is 3.14

From the information given,

Radius = 2 inches

Height = 15 inches

Therefore,

Surface area = (2 × π × 2²) + 2 × π × 2 × 15) = 8π + 60π

Surface area = 68π inches²

x=30

step-by-step explanation:

answer: ratio of volume of cone (with 3 times the height and equal diameter) to volume of cylinder is 2 to 1. the value of π is not used.

step-by-step explanation:

radius is diameter/2 = 4.

area of circle is π r^2.

volume of cylinder is height × area of base = hπr^2 = 3(4^2) π = 48π cubic inches.

not knowing the formula for volume of cone, i calculate it using calculus (which is for calculating things).

volume of cone is integral 0 to h area(y) dy. area(y) is π r(y)^2. r(y) runs r to zero as y runs zero to h, r(0) = r, r(h) = 0.

r(y) = r - r/h y

area(y) = π (r - r/h y)^2 = π (r^2 - 2r^2y/h + r^2y^2/h^2) = π r^2(1-2y/h+y^2/h^2)

antiderivative area(y) = π r^2 (y-y^2/h+y^3/(3h^2))

integral 0 to h = π r^2(h-h^2/h+h^3/(3h^2) - (0)) = π r^2(h - h + h/3) = π r^2(h/3) = π/3 r^2 h

volume of this cone is π/3(4^2)18 cubic inches.

= 6 16 π = 96π cubic inches.

cone has twice the volume, 96/48.

cone height is 6 times the cylinder.

ratio of volume formula: π r^2 cancels.

cone over cylinder ratio is 6h/3 to h, 2 to 1.