I would he would try to enter as the tide is rising, and leave as the tide is falling. Those things happen at all different times of day during a month. Hope it helps!!
Answer:
5.31x10⁻⁶ C
Explanation:
The cube is located 100 m altitude from the ground, so the superior face is at 100m and has E = 70 N/C, and the inferior face is at the ground with E = 130 N/C.
The electric field is perpendicular to the bottom and the top of the cube, so the total flux is the flux at the superior face plus the flux at the inferior face:
Фtotal = Ф100m + Фground
Where Ф = E*A*cos(α). α is the angle between the area vector and the field (180° at the topo and 0° at the bottom):
Фtotal = E100*A*cos(180°) + Eground*A*cos(0°)
Фtotal = 70A*(-1) + 130*A*1
Фtotal = 60A
By Gauss' Law, the flux is:
Фtotal = q/ε, where q is the charge, and ε is the permittivity constant in vacuum = 8.854x10⁻¹² C²/N.m²
A = 100mx100m = 10000 m²
q = 60*10000*8.854x10⁻¹²
q = 5.31x10⁻⁶ C
Answer:
0.50 moles of Cu
Explanation:
The balanced chemical equation for given synthetic reaction is,
2 Cu + S → Cu₂S
According to balance chemical equation,
1 mole of Cu₂S is produced by = 2 moles of Cu
So,
0.25 moles of Cu₂S will be produced by = X moles of Cu
Solving for X,
X = 0.25 mol × 2 mol / 1 mol
X = 0.50 moles of Cu
Hence, as the molar ratio of Cu to Cu₂S is 2:1 hence, to produce 0.25 moles of Cu₂S we will need 0.50 moles of Cu.
1) Use the fact that 1 mol of gas at STP occupies 22.4 liter
=> 1 mol / 22.4 l = x / 0.125 l => x = 0.125 l * 1 mol / 22.4 l = 0.00558 mol
2) Now use the molar mass of the gas
molar mass of CO2 ≈ 44 g / mol
Formula: molar mass = mass in grams / number of moles =>
mass in grams = molar mass * number of moles = 44 g/mol * 0.00558 moles
mass = 0.246 g
Answer: 0.246 g
