Answer:
The mass of the cube is 420.8 kg.
Explanation:
Given that,
Length of edge = 38.9 cm
Density 
We need to calculate the volume of cube
Using formula of volume
We need to calculate the mass of the cube
Using formula of density
Hence, The mass of the cube is 420.8 kg.
Answer:
Ordinal
Explanation:
There are four levels of measurement which include the nominal, ordinal, interval, and ratio. The data collected above is ordinal data as it qualifies the data and still indicates the ordering of the data. It gives the observer an idea of the range of data collected or its rating although mathematical calculations may not be done with it.
The other forms of data include the nominal which simply qualifies the data, the interval which qualifies the data but which the differences between the data can be obtained, and of course the data has no starting point. The ratio scale which is similar to the interval scale but which the ratios between the data obtained can be compared.
Answer:
The new resistance becomes half of the initial resistance.
Explanation:
The resistance of a wire is given by :
= resistivity of material
L and A are linear dimension
If the electrical wire is replaced with one having every linear dimension doubled i.e. l' = 2l and r' = 2r
New resistance of wire is given by :
The new resistance becomes half of the initial resistance. Hence, this is the required solution.
The correct answer is Option C) Sample C would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest.
As the coefficient of absorption would define the energy present in the reflected wave, the material C has the highest percentage of absorption i.e. 62% and would be best suitable to make a sound proof room.
Answer:
r = 4.44 m
Explanation:
For this exercise we use the Archimedes principle, which states that the buoyant force is equal to the weight of the dislodged fluid
B = ρ g V
Now let's use Newton's equilibrium relationship
B - W = 0
B = W
The weight of the system is the weight of the man and his accessories (W₁) plus the material weight of the ball (W)
σ = W / A
W = σ A
The area of a sphere is
A = 4π r²
W = W₁ + σ 4π r²
The volume of a sphere is
V = 4/3 π r³
Let's replace
ρ g 4/3 π r³ = W₁ + σ 4π r²
If we use the ideal gas equation
P V = n RT
P = ρ RT
ρ = P / RT
P / RT g 4/3 π r³ - σ 4 π r² = W₁
r² 4π (P/3RT r - σ) = W₁
Let's replace the values
r² 4π (1.01 10⁵ / (3 8.314 (70 + 273)) r - 0.060) = 13000
r² (11.81 r -0.060) = 13000 / 4pi
r² (11.81 r - 0.060) = 1034.51
As the independent term is very small we can despise it, to find the solution
r = 4.44 m
