plzzz help math question about cylinder?

Question

a cylindrical metal pipe has exernal diameter of 6cm and internal diameter of 4cm calculate the volume of metal in a pipe of length 1m. if 1cm of the metal weighs 8g (i.e the density of the metal is 8000kgm)find the weight of the pipe

Answer 1

Recognize that there are 2 cylinders, on with a radius of 2 cm and another with a radius of 3 cm. The height is 100 cm. Subtract the smaller volume from the larger volume. To get the volume. Then multiply by the weight of the metal per cm.
V=pi(r^2)(h)
V(l)=pi(3^2)(h)
V(l)=pi(9)(100)
V(l)=2827.233388
V(s)=pi(2^2)(100)
V(s)=pi(4)(100)
V(s)=1256.637061
Subtract to get about 1570.796327 cm^2. Multiply by 8 to get about 12566.37 g, or about 12.57 kg.

Answer 2

First make all dimensions equal, 1m = 100 cm

First Volume Equation (0utside)
pi X radius squared X height

pi X 9 x 100 = 900 pi Cubic cm

Second Volume (inside)

pi X 4 X 100 = 400 pi Cubic cm

Differrence is 500 pi Cubic cm

If you meant that a Cubic cm of pipe weighs 8 grams then the solution is 500 X pi X 8 which is approx. 12566 grams.

Answer 3

Volume of pipe is volume of 6cm pipe minus volume of 4 cm pipe. V= pi 3^2*100 + pi 2^2 *100 {The 100 converts m to cm}
V = 100*pi(3^2 +2^2) = 1300 cm^3.
Density = mass/volume, so
mass = 8000kg/m^3 * 1300 cm^3 / 10^6 cm^3/m^3
mass = 10.4 kg

Answer 4

Volume = pi r^2 h

Volume of big cylinder = pi (3^2) 100
Vol. of small cylinder (the open part inside the pipe)= pi (2^2)100

Subtract these to get the actual metal volume then multiply to get the weight

Answer 5

Calculate the cross-sectional area of the pipe by subtracting the area of the small circle (inside diameter) from the large circle (outside diameter) then multiply that by the length of pipe to get volume. Use consistent units (cm?). Multiply the volume (cubic cm) by the density (grams/cubic cm) to get the weight. (Your specified density may be in error - it must be grams/cubic cm or kgm per cubic meter, etc.).

Answer 6

find the total volume of a 6cm diameter pipe, the total volume of a 4cm cylinder. Subtract 4cm diameter volume from 6cm diameter volume. The mass and density is there to distract you

Answer 7

Outside area = π x 3² cm² = 9π cm²
Inside area = π x 2² cm² = 4π cm²
Area of metal = 9π - 4π = 5π cm²
Length = 100 cm
Volume = Area x Length = 5π x 100 cm³ = 500π cm³
If 1cm³ of metal weighs 8g, weight of pipe = 500π x 8 g
= 12560 g = 12.56 kg

Answer 8

Volume of cylinder
= 1/4pi(D^2-d^2)h
= 1/4pi(0.06^2-0.04^2)(1)
= 1/4(3.1428)(0.0036-0.0016)(1)
= 0.0015714 m^3
= 1571.4 cm^3

Density of metal = 8000kg/m^3

Weight of Pipe
= 0.0015714*8000
= 12.5712 kg

Answer 9

8.6 ounces