<span>d. The parallaxes beyond a few thousand light years are
too small to be measured with common instruments.
I'm not sure that parallax can even be used out to a few
thousand light years.
The NEAREST star to Earth has the BIGGEST parallax.
The star is Alpha Centauri. It's only 4 light years away
from us, and its parallax is 0.000206 of a degree !
I have no idea how astronomers can measure angles
so small ... and that's the BIGGEST parallax angle of
ANY star.</span>
Answer:
it is because it is quieter at night than in the daytime. Therefore it is easy to hear the sound far away. However, it is only one of the reasons. Actually, sound transmits farther at night may be related to refraction of sound waves! First, sound is the vibration of air, and it is a kind of wave motion.
Explanation:
Answer:
A) 4.035 × 10^(9) J
B) 9.29 × 10^(9) J
Explanation:
We are given;
Capacitance of the original capacitor; C = 1.33 F
Potential difference given to the original capacitor; V = 77.9 kV = 77.9 × 10³ V
A) The formula for Potential energy (U) for the original capacitor is given as:
U = ½CV²
Plugging in the relevant values, we have;
U = ½ × 1.33 × (77.9 × 10³)²
U = 4.035 × 10^(9) J
B) We are told that the capacitor with dielectric constant of 427, was replaced with one possessing a dielectric constant of 983.
Thus;
U = ½ × 1.33 × (983/427) × (77.9 × 10³)²
U = 9.29 × 10^(9) J
Answer:
The resistance of the tungsten coil at 80 degrees Celsius is 15.12 ohm
Explanation:
The given parameters are;
The resistance of the tungsten coil at 15 degrees Celsius = 12 ohm
The temperature coefficient of resistance of tungsten = 0.004/°C
The resistance of the tungsten coil at 80 degrees Celsius is found using the following relation;
R₂ = R₁·[1 + α·(t₂ - t₁)]
Where;
R₁ = The resistance at the initial temperature = 12 ohm
R₂ = The resistance of tungsten at the final temperature
t₁ = The initial temperature = 15 degrees Celsius
t₂ = The final temperature = 80 degrees Celsius
α = temperature coefficient of resistance of tungsten = 0.004/°C
Therefore, we have;
R₂ = 12×[1 + 0.004×(80 - 15)] = 15.12 ohm
The resistance of the tungsten coil at 80 degrees Celsius = 15.12 ohm.
