Hello!
The answer to your question is.
True. Coal is NOT considered a mineral because it is organic and made from the remains of once living things.
~Hope this Helps!~
F = ma
F = (1000 kg)•(5 m/s^2)
F = 5000 N
To solve this problem it is necessary to apply the concepts related to the condition of path difference for destructive interference between the two reflected waves from the top and bottom of a surface.
Mathematically this expression can be described under the equation

Where
n = Refractive index
t = Thickness
In terms of the wavelength the path difference of the reflected waves can be described as

Where
\lambda = Wavelenght
Equation the two equations we have that


Our values are given as
Wavelength of light



Therefore the minimum thickness of the oil for destructive interference to occur is approximately 34.0 nm
Explanation:
density = mass/ volume
in the question the mass is given in grams so will convert it into kg,
10 g = 0.01 kg
density= 0.01/ 20 = 1 / 2000 = 0.005 kg/m^3