Answer:
The net emissions rate of sulfur is 1861 lb/hr
Explanation:
Given that:
The power or the power plant = 750 MWe
Since the power plant with a thermal efficiency of 42% (i.e. 0.42) burns 9000 Btu/lb coal, Then the energy released per one lb of the coal can be computed as:

= 3988126.8 J
= 3.99 MJ
Also, The mass of the burned coal per sec can be calculated by dividing the molecular weight of the power plant by the energy released per one lb.
i.e.
The mass of the coal that is burned per sec 
The mass of the coal that is burned per sec = 187.97 lb/s
The mass of sulfur burned 
= 2.067 lb/s
To hour; we have:
= 7444 lb/hr
However, If a scrubber with 75% removal efficiency is utilized,
Then; the net emissions rate of sulfur is (1 - 0.75) × 7444 lb/hr
= 0.25 × 7444 lb/hr
= 1861 lb/hr
Hence, the net emissions rate of sulfur is 1861 lb/hr
The crate moves at constant velocity, this means that its acceleration is zero, so the net force acting on the crate is zero (Newton's second law).
There are only two forces acting on the crate: the force F applied by the worker and the frictional force, acting in the opposite direction:

, where

is the coefficient of friction and

is the mass of the crate. Since the net force should be equal to zero, the two forces must have same magnitude, so we have:

And so, this is the force that the worker must apply to the crate.
Answer:
Carbon 12
Explanation:
I don't 100% know what to put here, but...
When you remove the nucleus from an oxygen atom, almost everything of the base oxygen is essentially stripped away. Since almost everything is made of carbon, and Carbon 12 is one of the most common forms of Carbon, Carbon 12 would be what is left.
Answer: Option (c) is the correct answer.
Explanation:
Physical properties are the properties in which there is no change in chemical composition of a substance. On the other hand, chemical properties are the properties which change the chemical composition of a substance.
For example, when water boils at
then it changes into vapor state whereas when water freezes at
then it changes state from liquid to solid.
This means only physical state of water is changing and there is no change in chemical composition of water.
Hence, we can conclude that best option describing given information is that these are the physical changes water undergoes.