Zak, helping his mother rearrange the furniture in their living room, moves a 60 kg sofa 5.9 m with a constant force of 40 N. Wh
2 answers:
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Answer:
a. cosθ b. E.A
Explanation:
a.The electric flux, Φ passing through a given area is directly proportional to the number of electric field , E, the area it passes through A and the cosine of the angle between E and A. So, if we have a surface, S of surface area A and an area vector dA normal to the surface S and electric field lines of field strength E passing through it, the component of the electric field in the direction of the area vector produces the electric flux through the area. If θ the angle between the electric field E and the area vector dA is zero ,that is θ = 0, the flux through the area is maximum. If θ = 90 (perpendicular) the flux is zero. If θ = 180 the flux is negative. Also, as A or E increase or decrease, the electric flux increases or decreases respectively. From our trigonometric functions, we know that 0 ≤ cos θ ≤ 1 for 90 ≤ θ ≤ 0 and -1 ≤ cos θ ≤ 0 for 180 ≤ θ ≤ 90. Since these satisfy the limiting conditions for the values of our electric flux, then cos θ is the required trigonometric function. In the attachment, there is a graph which shows the relationship between electric flux and the angle between the electric field lines and the area. It is a cosine function
b. From above, we have established that our electric flux, Ф = EAcosθ. Since this is the expression for the dot product of two vectors E and A where E is the number of electric field lines passing through the surface and A is the area of the surface and θ the angle between them, we write the electric flux as Ф = E.A
Answer:
Option (B) is correct.
Explanation:
Given that the molecules of hydrogen gas () react with molecules of oxygen gas (
) in a sealed reaction chamber to produce water (
).
The governing equation for the reaction is
From the given, the only fact that can be observed that 2 moles of and 1 mole of
reacts to produce 2 moles of
.
As the mass of 1 mole of grams ... (i)
The mass of 1 mole of grams ...(ii)
The mass of 1 mole of grams (iii)
Now, the mass of the reactant = Mass of 2 moles of + mass 1 mole of
[ using equations (i) and (ii)]
grams.
Mass of the product = Mass of 2 moles of
[ using equations (iii)]
=36 grams
As the mass of reactants = mass of the product.
So, mass is conserved.
Hence, option (B) is correct.