Since the main objective of this experiment is to determine the effect of porosity on seedling growth that should be the only independent variable. In short, that is the only variable that should be different to ensure fair testing.
The answer should be B:
he plants seedlings in soils with different levels of porosity and equal levels of permeability.
Permeability is not what needs to be tested. If it changes, you may not be able to determine whether it was the porosity or permeability that cause changes.
Because dark line spectra result from passing white light through ionized gasses and plasmas, which is what the atmosphere of stars are made of. These frequencies are scattered by the star's atmosphere as it leaves the surface (photosphere) of the star, and don't make it to earth.
Answer:
The correct answer is "4.26 m".
Explanation:
Given:
Wavelength,
or,
Distance,
or,
Distance between the 1st and 2nd dark fringes,
As we know,
⇒
or,
⇒
By substituting the values, we get
Complete Question: A +10 nC charge is located at the origin. What is the electric field at the position (x2,y2)= (-5.0cm, 0cm)? Write electric field vector in component form.
E2x, E2y=? N/C
Answer:
Ex = -3.6*10⁴ N/C Ey=0
Explanation:
As the charge producing the field is positive, the direction of the field, which is the one that would take a positive test charge located in the point of interest, will be away from this point, pointing to the left.
If we choose the positive direction to be to the right, the electric field component along the x-axis will be negative.
The magnitude of the field can be obtained applying the electric field definition, and the Coulomb's Law to the charge in the origin, as follows:
E = k*q/r² = 9*10⁹N*m²/C²*10⁻⁸C/(0.05)² m² = 3.6*10⁴ N/C
As the electric field follows the same line as the electric force, it has only component on the x axis, so:
Ex = -3.6*10⁴ N/C
Ey = 0