Answer:
d_{b} = 2 d_{a}
Explanation:
The electrical resistance for a cylindrical wire is described by the expression
R = ρ L / A
The area of a circle is
A = π r²
r = d / 2
A = π d²/4
We substitute
R = ρ L 4 /π d²
Let's apply this expression to our case, they indicate that the resistance of wire A is 4 times the resistance of wire B
= 4 R_{b}
We substitute
ρ 4/π ² = 4 (ρ 4/π d_{b}²)
1 / d_{a}² = 4 / d_{b}²
d_{a} = d_{b} / 2
Answer:
The resultant velocity of the helicopter is .
Explanation:
Physically speaking, the resulting velocity of the helicopter (), measured in meters per second, is equal to the absolute velocity of the wind (
), measured in meters per second, plus the velocity of the helicopter relative to wind (
), also call velocity at still air, measured in meters per second. That is:
(1)
In addition, vectors in rectangular form are defined by the following expression:
(2)
Where:
- Magnitude, measured in meters per second.
- Direction angle, measured in sexagesimal degrees.
Then, (1) is expanded by applying (2):
(3)
If we know that ,
,
and
, then the resulting velocity of the helicopter is:
The resultant velocity of the helicopter is .
Answer
given,
For helium
Volume,V = 46 L
Pressure,P = 1 atm
Temperature,T = 25°C = 273 +25 = 298 K
R=0.0821 L . atm /mole.K
n₁ = ?
number of moles
we know
P V = n R T
n₁ = 1.89 moles
For oxygen
Volume,V = 12 L
Pressure,P = 1 atm
Temperature,T = 25°C = 273 +25 = 298 K
R=0.0821 L . atm /mole.K
n₂ = ?
number of moles
we know
P V = n R T
n₂ = 0.49 moles
Total volume of tank = 5 L
temperature of tank = 298 K
Partial pressure of helium
P₁ = 9.25 atm
Partial pressure of oxygen
P₂ = 2.39 atm
total pressure
P = P₁ + P₂
P = 9.25 + 2.39
P = 11.64 atm