Solar Nebula
Our solar system began forming within a concentration of interstellar dust and hydrogen gas called a molecular cloud. The cloud contracted under its own gravity and our proto-Sun formed in the hot dense center. The remainder of the cloud formed a swirling disk called of the solar nebula.
True is the correct answer
There’s many types of electricity that comes from an outlet, like [15A, 120 Volt Outlets] those are more common in older homes and can come in two versions [Two-pronged outlet and three-pronged version]
Answer:
-400km/hr
Explanation:
Velocity=displacement/time
=400/1
=400Km/hr
=-400km/hr (because west direction)
Answer:
option D
Explanation:
given,
Intensity of sound = 20 dB
distance = 15 m
intensity of sound is increased to = 50 dB
distance between the sound level = ?
Using relation
![L_2 = L_1 - |20(log \dfrac{r_2}{r_1})|](https://tex.z-dn.net/?f=L_2%20%3D%20L_1%20-%20%7C20%28log%20%5Cdfrac%7Br_2%7D%7Br_1%7D%29%7C)
L₁ = 20 dB L₂ = 50 dB r₁ = 15 m r₂ = ?
![log (\dfrac{r_2}{r_1}) = \dfrac{L_1 -L_2}{20}](https://tex.z-dn.net/?f=log%20%28%5Cdfrac%7Br_2%7D%7Br_1%7D%29%20%3D%20%5Cdfrac%7BL_1%20-L_2%7D%7B20%7D)
![\dfrac{r_2}{r_1}= 10^{\dfrac{|L_1 -L_2|}{20}}](https://tex.z-dn.net/?f=%5Cdfrac%7Br_2%7D%7Br_1%7D%3D%2010%5E%7B%5Cdfrac%7B%7CL_1%20-L_2%7C%7D%7B20%7D%7D)
![r_2 =r_1 10^{\dfrac{|L_1 -L_2|}{20}}](https://tex.z-dn.net/?f=r_2%20%3Dr_1%2010%5E%7B%5Cdfrac%7B%7CL_1%20-L_2%7C%7D%7B20%7D%7D)
![r_2 =15 \times 10^{\dfrac{|20-50|}{20}}](https://tex.z-dn.net/?f=r_2%20%3D15%20%5Ctimes%2010%5E%7B%5Cdfrac%7B%7C20-50%7C%7D%7B20%7D%7D)
![r_2 =15 \times 10^{-1.5}](https://tex.z-dn.net/?f=r_2%20%3D15%20%5Ctimes%2010%5E%7B-1.5%7D)
r₂ = 0.47 m
r₂ = 47 cm
hence, the correct answer is option D