# Metal tube

Calculate the metal tube mass 8dm long with the outer radius 5cm and the inner radius 4.5cm and 1cm3 of this metal is 9.5g.

Correct result:

m =  11.341 kg

#### Solution:

$r_{1}=4.5 \ \text{cm} \ \\ r_{2}=5 \ \text{cm} \ \\ l=8 \ dm \rightarrow cm=8 \cdot \ 10 \ cm=80 \ cm \ \\ \ \\ S=\pi \cdot \ r_{2}^2 - \pi \cdot \ r_{1}^2=3.1416 \cdot \ 5^2 - 3.1416 \cdot \ 4.5^2 \doteq 14.9226 \ \text{cm}^2 \ \\ \ \\ \ \\ V=S \cdot \ l=14.9226 \cdot \ 80 \doteq 1193.8052 \ \text{cm}^3 \ \\ \ \\ r=9.5 \ \text{g/cm}^3 \ \\ m_{1}=r \cdot \ V=9.5 \cdot \ 1193.8052 \doteq 11341.1495 \ \text{g} \ \\ \ \\ m=m_{1} \rightarrow kg=m_{1} / 1000 \ kg=11341.14947946 / 1000 \ kg=11.341 \ kg=11.341 \ \text{kg}$

Our examples were largely sent or created by pupils and students themselves. Therefore, we would be pleased if you could send us any errors you found, spelling mistakes, or rephasing the example. Thank you!

Please write to us with your comment on the math problem or ask something. Thank you for helping each other - students, teachers, parents, and problem authors.

Tips to related online calculators
Do you know the volume and unit volume, and want to convert volume units?
Tip: Our Density units converter will help you with the conversion of density units.
Do you want to convert mass units?

#### You need to know the following knowledge to solve this word math problem:

We encourage you to watch this tutorial video on this math problem:

## Next similar math problems:

• Three examples per-mille
A. Calculate 1.5 ‰ from 4.5 liters of blood. Express the result in milliliters. B. Calculate three ‰ from € 50,000. C. The tray they brought breakfast to the landlord's bed is made of an alloy that contains 830 ‰ of silver. How much silver did they use
• Cuboid edges
Calculate the volume and surface of a cuboid whose edge lengths are in the ratio 2: 3: 4 and the longest edge measures 10cm.
• Cube surfce2volume
Calculate the volume of the cube if its surface is 150 cm2.
• Spherical segment
Calculate the volume of a spherical segment 18 cm high. The diameter of the lower base is 80 cm, the upper base 60 cm.
• In the
In the rectangle ABCD, the distance of its center from the line AB is 3 cm greater than from the line BC. The circumference of the rectangle is 52 cm. Calculate the contents of the rectangle. Express the result in cm2.
Calculate the surface of a quadrilateral prism according to the input: Area of the diamond base S1 = 2.8 m2, length of the base edge a = 14 dm, height of the prism 1,500 mm.
• Alcohol from potatoes
In the distillery, 10 hl of alcohol can make from 8 t of potatoes. The rectangular field with dimensions of 600 m and 200 m had a yield of 20 t of potatoes per hectare. How many square meters of area are potatoes grown to obtain one liter of alcohol?
• Trip with compass
During the trip, Peter went 5 km straight north from the cottage, then 12 km west and finally returned straight to the cottage. How many kilometers did Peter cover during the whole trip?
• Divide in ratio
Line segment AB 12 cm long divide in a ratio of 5: 3. How long are the individual parts?
• Twice of radius
How many times does the surface of a sphere decrease if we reduce its radius twice?
• Concrete hatch
The concrete hatch for a round well has a diameter of 1300 mm and a thickness of 80 mm. Determine its weight in kg if the density of the concrete is 2545 kg/m3
• Ratio
Alena collected 7.8 kg of blueberries, 2.6 kg of blackberries, and 3.9 kg of cranberries. Express the ratio in the smallest natural numbers in this order.
• A bottle
A bottle full of cola weighs 1,320 g. If we drink three-tenths of it, it will weigh 1,008g. How much does an empty bottle weigh?
• Save trees
25 tons of old paper will save 1,600 trees. How many tons of paper is needed to save the 32 trees in the park?