The prison ball

Calculate the density of the material that the prison ball is made from if you know its diameter is 15cm and its weight is approximately 2.3kg. With the help of mathematical-physicochemical tables estimate what material the ball is made from.

Correct result:

h =  1301.5338 kg/m³

Solution:

$$\begin{gathered} D=15\text{ cm}\to \text{ m}=15\mathrm{/}100\text{ m}=0.15\text{ m } \\ m=2.3\text{ kg } \\ r=D\mathrm{/}2=0.15\mathrm{/}2={\displaystyle \frac{3}{40}}=0.075\text{ m } \\ V={\displaystyle \frac{4}{3}}\cdot \pi \cdot r^3={\displaystyle \frac{4}{3}}\cdot 3.1416\cdot 0.075^3\doteq 0.0018{\text{m}}^3 \\ h=m\mathrm{/}V=2.3\mathrm{/}0.0018=1301.5338{\text{kg/m}}^3 \end{gathered}$$

Try another example

Showing 0 comments:

Related math problems and questions:

• Steel tube
  The steel tube has an inner diameter of 4 cm and an outer diameter of 4.8 cm. The density of the steel is 7800 kg/m³. Calculate its length if it weighs 15 kg.
• Cone from cube
  The largest possible cone was turned from a 20 cm high wooden cube. Calculate its weight if you know that the density of wood was 850 kg/m³
• Bricks
  Openings in perforated bricks occupy 10% and brick has dimensions 30 cm, 15 cm and 7.5 cm. Calculate a) the weight of a perforated bricks, if you know that the density of the full brick material is p = 1800 kg/m³ (1.8 kg/dm³) b) the number of perforated
• Cuboid 5
  Calculate the mass of the cuboid with dimensions of 12 cm; 0.8 dm and 100 mm made from spruce wood (density = 550 kg/m³).
• Density - simple example
  Material of density of 1485 kg/m³ occupies a container volume of 65 cm³. What is its mass?
• Brass ball
  What is the weight of a hollow brass ball, the outer diameter of which is 16 cm and the wall thickness is 2 cm, while the density of brass is ϱ = 8.5 g
• Iron sphere
  Iron sphere has weight 100 kg and density ρ = 7600 kg/m³. Calculate the volume, surface and diameter of the sphere.
• Hollow sphere
  The steel hollow sphere floats on the water plunged into half its volume. Determine the outer radius of the sphere and wall thickness, if you know that the weight of the sphere is 0.5 kg and the density of steel is 7850 kg/m³
• Railway wagon
  The railway wagon holds 75 m³ load. Wagon can carry a maximum weight of 30 tonnes. What is the maximum density that may have material with which we could fill this whole wagon? b) what amount of peat (density 350 kg/m³) can carry 15 wagons?
• Oak cuboid
  Oak timber is rectangular shaped with dimensions of 2m, 30 cm and 15 cm. It weight is 70 kg. Calculate the weight 1 dm³ of timber.
• Copper plate
  Calculate the thickness of the copper plate with a density 8.7 g/cm³ measuring 1.5 meters and 80 cm and its weight is 3.65 kg
• The glass
  1 m³ of glass weighs 2600 kg. Calculate the weight of the glass glazing panel with dimensions of 2.5 m and 3.8 m if the thickness of the glass is 0.8 cm
• Wood cuboid
  What is the weight of the wood cuboid 15 cm, 20 cm, 3 m if 1 m³ wood weighs 800 kg?
• Wall thickness
  The hollow metal ball has an outside diameter of 40 cm. Determine the wall thickness if the weight is 25 kg and the metal density is 8.45 g/cm³.
• Copper wire
  What is the weight in kg of copper wire 200 m long with a diameter of 0.6 cm, if the density of copper is 8.8 kg?
• Sphere
  The surface of the sphere is 12100 cm², and the weight is 136 kg. What is its density?
• Oak trunk
  Calculate in tonnes the approximate weight of a cylindrical oak trunk with a diameter of 66 cm and a length of 4 m, knowing that the density of the wood was 800 kg/m³.