Answer:
a) The US power rating for the european bulb must be 27.27 W
b) The current in the United Stated for the european bulb is 0.227A
Explanation:
First of all the bulb is not going to light in 120V like it does in 220V, the bright is going to be much lower (near 1/4). Now, lets take a look on a circuit perspective:
The bulb in a circuit is modeled like a simple resistor, so we have a resistor conected to a voltage source, see figure 1. There we have a current given by:
Where is the 220v Input voltage, R is the resistance from the bulb. In the problem we have the power consumption in watts given by:
Clearing
Now, from ohm's law
So 484 ohm is the resistance from the bulb.
Now in the circuit lets replace the voltage source from 220v to 120v and lets calculate the current, and the power consuptiom
And the power consuptiom:
Answer:
a) 1511 MW
b) 44%
Explanation:
The thermal power will be the electric power plus the heat taken away by the cooling water.
Qt = P + Qc
The heat taken away by the water will be:
Qc = G * Cp * (t1 - t0)
The Cp of water is 4180 J/(kg K)
The density of water is 1 kg/L
Then
G = 1.17 * 10^8 L/h * 1 kg/L * 1/3600 h/s = 32500 kg/s
Now we calculate Qc
Qc = 32500 * 4180 * (29.8 - 23.6) = 842*10^6 W = 842 MW
The total thermal power then is
Qt = 669 + 842 = 1511 MW
The efficiency is
η = P / Qt
η = 669 / 1511 = 44%
For this problem, we use the Coulomb's Law whose equation is written as
F = kQ₁Q₂/d²
where
F is the electric force
k is the Coulomb's constant equal to 8.98755×10⁹ N·m²/c²
Q₁ and Q₂ are two charges
d is the distance between two charges
First, let's compute the force between the two positive charges denotes as F₁.
F₁ = (8.98755×10⁹ N·m²/c²)(+53×10⁻⁶ C)(+53×10⁻⁶ C)/(35 cm * 1 m/100cm)²
F₁ = 206.09 N
Next, let's compute the force between the positive and the negative charges denotes as F₂.
F₂ = (8.98755×10⁹ N·m²/c²)(+53×10⁻⁶ C)(-53×10⁻⁶ C)/(35 cm * 1 m/100cm)²
F₂ = -206.09 N
The net force is the sum of the two forces.
Net Force = 206.09 - 206.09 = 0
Therefore, the net force experienced by the positive charge is zero.