Answer:
1. Soil vapor extraction - 3
2. Air sparging - 1
3. bioventing - 4
4. Natural attenuation -2
Explanation:
Soil vapor extraction - Soil vapor extraction (SVE) is the method in which perforated pipes are used into the soil and air is injected through the pipes. Contamination in soil then removed through perforation in pipes and disposed into an off-gas treatment unit.
Air sparging - In air sparging process air is injected in bubble form that remediates groundwater by volatilizing contaminants and enhancing biodegradation.
Bioventing - In bioinventing process low air flow rates are used that provide enough oxygen to sustain microbial activity in the soil and remove other contamination form the soil.
Natural attenuation - Natural attenuation is a natural process of environmental remediation which reduce the toxicity, mass, or concentration of contaminants in soil without human intervention.
The correct option is C) The angle between the vectors is 120°.
Why?
We can solve the problem and find the correct option using the Law of Cosine.
Let A and B, the given two sides and R the resultant (sum),
Then,

So, using the law of cosines, we have:

Hence, we have that the angle between the vectors is 120°. The correct option is C) The angle between the vectors is 120°
Have a nice day!
It would be negative regardless of what you define as a positive direction.
Answer:
The answer is 2,416 m/s. Let's jump in.
Explanation:
We do work with the amount of energy we can transfer to objects. According to energy theory:
W = ΔE
Also as we know W = F.x
We choose our reference point as a horizontal line at the block's rest point.<u> At the rest, block doesn't have kinetic energy</u> and <u>since it is on the reference point(as we decided) it also has no potential energy.</u>
Under the force block gains;
W = F.x → 
In the second position block has both kinetic and potential energy. Following the law of conservation of energy;
W = ΔE = Kinetic energy + Potantial Energy
W = ΔE = 
Here we can find h in the triangle i draw in the picture using sine theorem;
In a triangle 
In our situation
→ 
Therefore

→ 