Answer:
21st of December
Explanation:
In the northern hemisphere there occurs winter solstice on 21st of December. During this time, the tilt of the earth in the northern hemisphere is away from the sun. So the places near and at Antarctica, there will be sunlight for about 24 hours and the sun does not set on this particular day.
And, on the other hand, the places near the Arctic circle experiences darkness for about 24 hours and the sun does not rise on this specific day.
Answer:
reactants are needed to start a chemical reaction
Explanation:
am I correct
Alternating compressions and rarefactions produce a wave. One compression and one rarefaction is called a wavelength.
Compression happens when molecules are forced, or pressed, together. Rarefaction occurs when molecules are given extra space and allowed to expand.
Answer:
Explanation:
By the Law of Sines,
From Newton's Law,
And the last equation again from Newton's Law,
Then if we collect all equations together,
Thus,
Answer:
Explanation:
At resonance ω₀L = 1 / ω₀C , L is inductance and C is capacitance .
C = 1 / ω₀²L , ω₀ = 5.1 x 10⁵ . ( given )
voltage over resistance = R I , R is resistance and I is current
voltage over inductance = Iω₀L
R I / Iω₀L = 60 / 40
R / ω₀L = 3 / 2
L = 2 R / 3 ω₀
= 2 x 121 / 3 x 5.1 x 10⁵
= 15.81 x 10⁻⁵
C = 1 / ω₀²L
= 1 / (5.1 x 10⁵)² x 15.81 x 10⁻⁵
= .002432 x 10⁻⁵
= 24.32 x 10⁻⁹ F
Let the angular frequency required be ω
Tan 45 = (ωL - 1 / ωC) / R
ωL - 1 / ωC = R
ω²LC - 1 = R ωC
ω²LC = 1 + R ωC
ω² x 15.81 x 10⁻⁵ x 24.32 x 10⁻⁹ = 1 + 121 x ω x 24.32 x 10⁻⁹
ω² x 384.5 x 10⁻¹⁴ = 1 + 2942.72 x10⁻⁹ω
ω² - 7.65 x 10⁶ ω - 1 = 0
ω = 7.65 x 10⁶
frequency = 7.65 x 10⁶ / 2π
= 1.22 x 10⁶ Hz
