Math..math..math. Any help appreciated!?

Question

Hi. Any helpwould be appreciated. Thanks.

1) How many square feet of paper do you need to cover a cube with a side 10 inches long? Round your answer to two decimal places.

2) How many cubic inches of material do you need to make a solid rubber ball with a diameter of 3 inches? Round your answer to two decimal places.

If you could at least explain the steps I shouldgo through that'll be enough.Thanks a bunch.

Answer 1

1.) A cube is a six sided polyhedron, with each side being a square with area l^2. (where l is the length of one side.

Therefore, the surface area is 6l^2.

l = 10 inches
6 * 10^2 = 600 in^2
600 in^2 = 600/144 ft^2 = 4.17 ft^2.(solution!)
(remember: 12 in = 1 ft, so 12^2 in^2 = 1 ft^2)

2.) The volume of a sphere is 4/3 * pi* r^3, where r is the radius.
d = 2r, so the r is 1.5 in.

4/3 * 3.14159 * 1.5^3 = 14.14 in^3.

Answer 2

1) Convert ten inches into feet (10/12, or 5/6, which should be a decimal). Square this value (square feet needed for one side), then multiply by six (a cube has six sides).

2) I believe the volume of a sphere is (4/3)(pi)(r^3). You are given the diameter as 3 inches, so the radius is 1.5 inches. Substitute that in and you should get your answer.

Hope that helps.

Answer 3

1 - a cube has six sides, so you need to find the area of 6 squares that are each 10 inches across. Just find the area of a square 10 inches across and multiply by 6.

2 - the formula for volume of a sphere is 4/3 times Pi times the square of the radius. The radius is half the diameter, so 4/3 time pi times ( 1.5 squared )

Answer 4

1. surface area of a cube is 6 a^2=600 sq.inch
600/144 sft=4.17 sft
2.vol of a sphere=(4/3)pi*r^3
(4/3)*3.14*3^3/8=113.04/8
=14.13Cubic Inch

Answer 5

Question 1) 4.166cu feet
Question 2) Radius = 1.5"
Circumferance =9.4248
Times this by pie

Area=28.274
This is the correct answer, the others above gave you the volume.

Answer 6

1. 10/12=0.83 ft
Area=0.83*0.83=0.68 sq ft (per side)
Since a cube has 6 sides, 0.68*6=4.13 (approx)

2. V=(4/3)*pi*r^3
diameter=3 in, so the radius =3/2 =1.5 inches. pi=3.14, so
(4/3)*3.14*(1.5)^3=14.10 (approx)

Answer 7

Using "truly" means I have to give a serious answer. I never put my head to pillow that I don't thank God that I know what it's like to have one under my head. I always spend a bit thinking of all the people in the world who will never know that comfort. I think of those who will never know a bed or warmth or coolness when needed. I think of those who are hungry. I hurt for them.

Answer 8

(10/12) x (10/12) x 6 = 4.17 square feet.