Answer : 
Explanation :
Given that
Radius of sphere 
The distance between the centers of the two spheres is

The charge of the sphere 
The magnitude of the repulsive force between the charges pushing them a part is
Using coulomb law




Hence, this is the required solution.
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.
Answer:
0.25 m.
Explanation:
We'll begin by calculating the spring constant of the spring.
From the diagram, we shall used any of the weight with the corresponding extention to determine the spring constant. This is illustrated below:
Force (F) = 0.1 N
Extention (e) = 0.125 m
Spring constant (K) =?
F = Ke
0.1 = K x 0.125
Divide both side by 0.125
K = 0.1/0.125
K = 0.8 N/m
Therefore, the force constant, K of spring is 0.8 N/m
Now, we can obtain the number in gap 1 in the diagram above as follow:
Force (F) = 0.2 N
Spring constant (K) = 0.8 N/m
Extention (e) =..?
F = Ke
0.2 = 0.8 x e
Divide both side by 0.8
e = 0.2/0.8
e = 0.25 m
Therefore, the number that will complete gap 1is 0.25 m.
I beleive she isnt doing any work due to holding the box motionless, you must be exerting a force in the direction of the box motion. If she is just standing there holding the box their isn't no work becuase no distance has been covered. work = force = distance.