Answer:
b
Explanation:
i took the quiz i think its right
Answer:
<h2>
d₂ = 3d</h2><h2>
The diameter of the second wire is 3 times that of the initial wire.</h2>
Explanation:
Using the formula for calculating the resistivity of an object to find the diameter.
Resistivity P = RA/L
R is the resistance of the material
A is the cross sectional area
L is the length of the material
Since A = πd²/4
P = R( πd²/4)/L
P = Rπd²/4L ... 1
If the second wire of the same material and length is found to have resistance R/9, the resistivity of the second material will be;
P₂ = (R/9)A₂/L₂
P₂ = (R/9)(πd₂²/4)/L₂
P₂ = (Rπd₂²/36)/L₂
P₂ = (Rπd₂²)/36L₂
Since the length and resistivity are the same;
P = P₂ and L =L₂
Equating 1 and 2;
Rπd²/4L = (Rπd₂²)/36L₂
Rπd²/4L = (Rπd₂²)/36L
d² = d₂²/9
d₂² = 9d²
Taking the square root of both sides;
√d₂² = √9d²
d₂ = 3d
Therefore the diameter of the second wire is 3 times that of the initial wire
Answer:
4m/s
Explanation:
May be different considering how long the pole is and how heavy the firefighter is.
Answer:
(4) A = 3 A, A₂ = 11 A
(5) 7 A
Explanation:
(4)
From the diagram,
A = 3+6+2
A = 11 A
V = A₂R
A₂ = V/R₂............ Equation 1
Given: V = 12 V, R₂ = 4 Ω
Substitute these values into equation 1
A₂ = 12/4
A₂ = 3 A
(5) Applying,
V = IR'
I = V/R'............ Equation 1
Where V = Voltage, I = cuurent, R' = total resistance.
But,
1/R' = (1/3)+(1/4)
1/R' = (3+4)/12
1/R' = 7/12
R' = 12/7 Ω
Given: V = 12 V
Substitute these values into equation 1
I = 12/(12/7)
I = 7 A
Therefore
A = 7 A
