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:
M1 V1 = M1 V2 + M2 V3 conservation of momentum
V2 = (M1 V1 - M2 V3) / M1 where V2 = speed of M1 after impact
V2 = (3 * 9 - 1.5 * 5) / 9 = (27 - 7.5) / 9 = 2.17 m/s
Note: All speeds are in the same direction and have the same sign
Answer:
C) steel turning to rust in salt air
Explanation:
The missing options are:
A) ice melting to form liquid water
B) water boiling to form steam
C) steel turning to rust in salt air
D) sugar dissolving into hot coffee
In a chemical change the atoms of the reacting compounds are reordered forming new compounds. In a chemical change, new compounds appear, but in a physical change not.
Then, change of states like ice melting and water boiling are not chemical changes.
During steel rust, components of steel, like iron, are oxidized, that is, reacts with oxygen forming oxides.
The dissolution of sugar into hot coffee is a physical change in which sugar molecules get further apart in the coffee, but they don't change.
Answer:
The value of each charge is 4.22 x 10⁻⁵ C
Explanation:
Given;
distance between the two identical charges, d = 2 m
the force of repulsion between these two charges, F = 4N
Apply Coulomb's law;
Therefore, the value of each charge is 4.22 x 10⁻⁵ C
Answer: The force constant k is 10600 kg/s^2
Step by step:
Use the law of energy conservation. When the elevator hits the spring, it has a certain kinetic and a potential energy. When the elevator reaches the point of still stand the kinetic and potential energies have been transformed to work performed by the elevator in the form of friction (brake clamp) and loading the spring.
Let us define the vertical height axis as having two points: h=2m at the point of elevator hitting the spring, and h=0m at the point of stopping.
The total energy at the point h=2m is:
The total energy at the point h=0m is:
The two Energy values are to be equal (by law of energy conservation), which allows us to determine the only unknown, namely the force constant k:
