a 0.25 cubic inch of paint is painted onto a circular piece of paper w/ a diamter of 20 inches. what is the thickness of the paint on the paper?
do i need to use the diameter = 2r to figure out the thickness?
thanks for the help.
2006-09-04 06:17:43 · 7 answers · asked by shih rips 6 in Science & Mathematics ➔ Mathematics
yes,d=2r and area=pi*r^2
thickness=volume/area
=0.25/3.14*100
=0.25/314=0.000796178 in
2006-09-04 06:22:46 · answer #1 · answered by raj 7 · 0⤊ 0⤋
Find the area of the circle:
A = ∏D²/4 = 100∏ in.sq
Find the volume of the paint:
V = T x A = 0.25 in.cu where T = Thickness of the paint
Substitute and solve for T:
T = V/A = 0.25 in.cu/100∏ in.sq = 1/400∏ in.
2006-09-04 06:45:21 · answer #2 · answered by jparnelli 1 · 0⤊ 0⤋
The problem is really one of solid geometry.
You are talking about a cylinder that has a volume of 0.25 cu-in.
The volume of a cylinder is pi x r x r x h
In this case h is the thickness of the paint.
So....0.25=pi x (20/2) x (20/2) x h
You are correct in that the radius must be used in the calculation and the radius r = diameter/2
Solving we have 0.25= pi x 10 x 10 x h
continuing we have 0.25 = pi x 100h or
100h = 0.25/pi
therefore h = (0.25/pi) / 100
h= 1/(4 x 100 x pi)
h=1/(400 x pi)
h=1/(400 x 3.14) = 1/ 1256
h=.000796 which can me rounded to .0008 inches
This is 8 ten thousandths of an inch thick
Hope this helps
2006-09-04 08:03:28 · answer #3 · answered by Carl 3 · 0⤊ 0⤋
Diameter = 20inc hes
Radius = 10 inchess
Area of Paper=pi r^2=3.14x100=314 sq inches..........i
Volume of paint = 0.25 cubic inche
Thickness of paint = Volume/ area
=0.25/314
=0.000796178 inches
=0.0008 inches approximation
2006-09-04 07:42:54 · answer #4 · answered by Amar Soni 7 · 0⤊ 0⤋
You have the volume of the paint. You can work out the area of the circular piece of paper. Area x Height= volume of paint.
Work out the area......you have the volume so now work out the height which will be the thickness of the paint.
2006-09-04 06:25:14 · answer #5 · answered by Andre v 1 · 0⤊ 0⤋
2. 3,600 = length X width X height 3,600 = 30 X 15 X height 3,600/(30 X 15) = height 8 toes = height The potential is yet yet another be wakeful for the quantity = l X w X h 4. idk 6. idk 15. Perimeter = 2l + 2w Perimeter = 2(4 X 6) + 2(3 X 6) Perimeter = 40 8 + 36 Perimeter = 80 4 13. 2x - 5 = 7 2x = 12 x = 6 17. section = length X width A(room a million) = 13 X 12 = 156 A(room 2) = 321 - 156 = one hundred sixty 5 one hundred sixty 5 = 11 x length length = 15
2016-11-24 21:19:45 · answer #6 · answered by ? 4 · 0⤊ 0⤋
area = 100*Pi sq inches
.25/(100*Pi) = thickness
1/(400*Pi)
.000795775... in = thickness
2006-09-04 06:37:53 · answer #7 · answered by bob h 3 · 0⤊ 0⤋