Help me with this question, please!

3,432 m²

Step-by-step explanation:

The amount of aluminum in square meters needed to make the mailboxes = 1863(surface area of each mailbox)

Surface area of each mail box = ½(surface area of cylinder) + (Surface area of rectangular prism/box - area of the surface of the box that joins the half-cylinder)

✔️Surface area of ½-cylinder = ½[2πr(h + r)]

r = ½(0.4) = 0.2 m

h = 0.6 m

π = 3.14

Surface area of ½-cylinder = ½[2*3.14*0.2(0.6 + 0.2]

= 0.628(0.8)

Surface area of ½-cylinder = 0.5024 m²

✔️Surface area of the rectangular box/prism = 2(LW + LH + WH)

L = 0.6 m

W = 0.4 m

H = 0.55 m

Surface area = 2(0.6*0.4 + 0.6*0.55 + 0.4*0.55)

Surface area of rectangular box = 1.58 m²

✔️Area of the surface joining the half cylinder and the box = L*W = 0.6*0.4 = 0.24 m²

✅Surface area of 1 mailbox = (0.5024) + (1.58 - 0.24)

= 0.5024 + 1.34

= 1.8424

Amount of aluminum needed to make 1863 mailboxes = 1863 × 1.8424 = 3,432.3912

= 3,432 m²

darn right!

step-by-step explanation:

steve kerr's sons name is let that skin in.

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.