Answer:
I = 21.13 mA ≈ 21 mA
Explanation:
If
I₁ = 5 mA
L₁ = L₂ = L
V₁ = V₂ = V
ρ₁ = 1.68*10⁻⁸ Ohm-m
ρ₂ = 1.59*10⁻⁸ Ohm-m
D₁ = D
D₂ = 2D
S₁ = 0.25*π*D²
S₂ = 0.25*π*(2*D)² = π*D²
If we apply the equation
R = ρ*L / S
where (using Ohm's Law):
R = V / I
we have
V / I = ρ*L / S
If V and L are the same
V / L = ρ*I / S
then
(V / L)₁ = (V / L)₂ ⇒ ρ₁*I₁ / S₁ = ρ₂*I₂ / S₂
If
S₁ = 0.25*π*D² and
S₂ = 0.25*π*(2*D)² = π*D²
we have
ρ₁*I₁ / (0.25*π*D²) = ρ₂*I₂ / (π*D²)
⇒ I₂ = 4*ρ₁*I₁ / ρ₂
⇒ I₂ = 4*1.68*10⁻⁸ Ohm-m*5 mA / 1.59*10⁻⁸ Ohm-m
⇒ I₂ = 21.13 mA
NOTE: The given question is incomplete.
<u>The complete question is given below.</u>
A student measures the speed of yellow light in water to be 2.00 x 10⁸ m/s. Calculate the speed of light in air.
Solution:
Speed of yellow light in water (v) = 2.00 x 10⁸ m/s
Refractive Index of water with respect to air (μ) = 4/3
Refractive Index = Speed of yellow light in air / Speed of yellow light in water
Or, The speed of yellow light in air = Refractive Index × Speed of yellow light in water
or, = (4/3) × 2.00 x 10⁸ m/s
or, = 2.67 × 10⁸ m/s ≈ 3.0 × 10⁸ m/s
Hence, the required speed of yellow light in the air will be 3.0 × 10⁸ m/s.
Sure, if the mortality (death) rate is even higher than the birth rate.
The answer will be 50N.
This is because the spring reads weight and weight is mass times acceleration due to gravity.5kg*10m/s2=50N
