John used smothering as the method to control the harmful invasive plants in his orchard. Smothering is an example of a manual method of control and it works best in a small population of invasive species. Smothering involves covering the invasive species with a barrier that is highly impenetrable for one growing season in order to prevent these species from thriving in the environment.
Answer:
D) equal to the flux of electric field through the Gaussian surface B.
Explanation:
Flux through S(A) = Flux through S (B ) = Charge inside/ ∈₀
Answer:
The correct answer is 
Explanation:
The formula for the electron drift speed is given as follows,

where n is the number of of electrons per unit m³, q is the charge on an electron and A is the cross-sectional area of the copper wire and I is the current. We see that we already have A , q and I. The only thing left to calculate is the electron density n that is the number of electrons per unit volume.
Using the information provided in the question we can see that the number of moles of copper atoms in a cm³ of volume of the conductor is
. Converting this number to m³ using very elementary unit conversion we get
. If we multiply this number by the Avagardo number which is the number of atoms per mol of any gas , we get the number of atoms per m³ which in this case is equal to the number of electron per m³ because one electron per atom of copper contribute to the current. So we get,

if we convert the area from mm³ to m³ we get
.So now that we have n, we plug in all the values of A ,I ,q and n into the main equation to obtain,

which is our final answer.
Answer: 2. Solution A attains a higher temperature.
Explanation: Specific heat simply means, that amount of heat which is when supplied to a unit mass of a substance will raise its temperature by 1°C.
In the given situation we have equal masses of two solutions A & B, out of which A has lower specific heat which means that a unit mass of solution A requires lesser energy to raise its temperature by 1°C than the solution B.
Since, the masses of both the solutions are same and equal heat is supplied to both, the proportional condition will follow.
<em>We have a formula for such condition,</em>
.....................................(1)
where:
= temperature difference
- c= specific heat of the body
<u>Proving mathematically:</u>
<em>According to the given conditions</em>
- we have equal masses of two solutions A & B, i.e.

- equal heat is supplied to both the solutions, i.e.

- specific heat of solution A,

- specific heat of solution B,

&
are the change in temperatures of the respective solutions.
Now, putting the above values


Which proves that solution A attains a higher temperature than solution B.
According to Newton's second law of motion, Force is the product of mass and acceleration of the object.
So, F = m * a
Here, m = 210 Kg
a = 2.4 * 10⁵ m/s²
Substitute their values,
F = 210 * 2.4 * 10⁵ N
F = 504 * 10⁵ N
F = 5.04 * 10⁷ N
In short, Your Answer would be Option B
Hope this helps!