Answer:
The Bulk density = 1.3 g/cm³
the porosity of the sample is 132 cm³
Explanation:
Given:
Volume of cylinder = 260 cm³
Mass of container and the soil = 403 g
Mass of the empty container = 65 g
Thus,
The mass of the soil is = 403 - 65 = 338 g
Now,
The Bulk density = 
or
The Bulk density = 
or
The Bulk density = 1.3 g/cm³
also,
average particle density for mineral soil is usually given as 2.65 g/cm³
i.e the air present in the given soil sample has reduced its density from 2.65 g/cm³ to 1.3 g/cm³
The mass of the whole sample = Volume × Density
= 260 × 2.65
= 689 gm
but,
The actual mass of the dry sample = 338 g
thus,
Mass of air in the sample = 689 - 338 = 351 g
Therefore,
the volume of 351 g soil = 
= 
= 132.45 cm³
so the porosity of the sample is 132 cm³
Answer: The correct answer is : (2) all inorganic rocks except igneous rocks are formed from other rocks
Explanation: Igneous rocks are formed by the solidification of magma, the process is slow if it is in the crust and fast if it is on the surface.
Sedimentary rocks are formed on the surface of the earth by processes of erosion and alteration of pre-existing rocks.
Metamorphic rocks have been formed by the evolution of another previous rock due to the environment to which it is subjected that may be hotter, colder or of a different pressure.
Answer:
Listed
Explanation:
Five common energy sources are
1. Coal and Petroleum
2. Nuclear energy
3. Geothermal power
4. Solar
5. Wind
conservation of energy is very important in current situation of energy crisis. Efficient utilization of energy sources must be one of the top priority of nations.
1. Procurement of alternate sources of energies to reduce dependence on convectional sources of energies.
2.vehicle running on electric and hydrogen fuels should developed so that sources of coal and petroleum are conserved.
3. Production of solar and wind energies should be on large scale so that their cost become cheaper and available for common people
Nationalism allows people to express devotion to their nation.
