Масса (килограмм), длина (метр) и время (секунда) - это 3 из 7 основных единиц в системе СИ.
Базовые единицы произвольно определены как то, что они есть, поэтому они не могут быть получены.
Все другие единицы в системе СИ являются производными от 7 основных единиц, таких как скорость (метр / секунда).
Остальные 4 - это температура (Кельвин), количество вещества (моль), электрический ток (ампер) и светимость (кандела).
Answer: Δβ (dB) = -13.1dB
Explanation:
The intensity of sound is inversely proportional to the square of the distance between them.
I ∝ 1/r²
I₁/I₂= r₂²/r₁² .....1
When the listener increases his distance from the source by a factor of 4.49.
Then,
r₂/r₁= 4.49
From equation 1
I₁/I₂ = (4.49)²
I₁/I₂ = 20.16
I₂/I₁ = 1/20.16
The change in sound intensity in dB can be given as
Δβ (dB) = 10 log(I₂/l₁) = 10log(1/20.6) = -13.1dB
Answer:
ΔV = 0.98 L
Explanation:
First, we will calculate the increased volume using Charles' Law:
where,
V₁ =initial volume = 18.9 L
V₂ = final volume = ?
T₁ = initial temperature = 15°C + 273 = 288 k
T₂ = final temperature = 30°C + 273 = 303 k
Therefore,
V₂ = 19.88 L
Now, we calculate the change in volume:
ΔV = V₂ - V₁ = 19.88L - 18.9 L
<u>ΔV = 0.98 L</u>
This is the volume of gasoline that will spill out.
Answer:
The latent heat of fusion of water is 334.88 Joules per gram of water.
Explanation:
Let the latent heat of ice be 'x' J/g
1) Thus heat absorbed by 100 gram of ice to get converted into water equals
2) heat energy required to raise the temperature of water from 0 to 25 degree Celsius equals
Thus total energy needed equals
3) Heat energy released by the decrease in the temperature of water from 25 to 11 degree Celsius is
Now by conservation of energy we have