<span><span>Fuel Extraction and Production – Water is a critical resource for the drilling and mining of natural gas, coal, oil, and uranium. In many cases, fuel extraction also produces wastewater, as with natural gas and oil wells and coal slurry ponds.
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Fuel Refining and Processing – Oil, uranium, and natural gas all require refining before they can be used as fuels – a process that uses substantial amounts of water.
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Fuel Transportation – Water is used to transport coal through slurries — pipelines of finely ground coal mixed with water — and to test energy pipelines for leaks.[1]</span><span>Emissions Control – Many thermoelectric power plants emit sulfur, mercury, particulates, carbon dioxide, and other pollutants, and require pollution control technologies. These technologies also require significant amounts of water to operate.</span></span>
Answer:
what is the question. . .
A large force is required to accelerate the mass of the bicycle and rider. Once the desired constant velocity is reached, a much smaller force is sufficient to overcome the ever-present frictional forces.
Answer:
1.65
Explanation:
The equation of the forces along the horizontal direction is:
(1)
where
F = 65 N is the force applied with the push
is the frictional force
m = 4 kg is the mass
is the acceleration
The force of friction can be written as 
(2), where
is the coefficient of kinetic friction
R is the normal force exerted by the floor
The equation of forces along the vertical direction is
(3)
since the bookcase is in equilibrium. Substituting (2) and (3) into (1), we find
And solving for ,
