Sound travels fastest through matter in the <em>solid state</em>.
I know this from having answered a huge number of Brainly questions that required me to look up things like this:
-- Speed of sound in air . . . about 340 m/s
-- Speed of sound in sea-water . . . about 1,500 m/s
-- Speed of sound in steel . . . about 5,960 m/s
The answer is B
How quickly are the stars in the Milky Way moving away from Earth
Explanation:
Wavelength in an emission spectrum,
The energy of an electron is given by :

Where
h is the Planck's constant
c is the speed of light
For 435 nm, the energy of the electron will be :


We know that 
So, 
So, E = 2.86 eV
The energy of the electron dropping from one energy level is 2.86 eV. We know that,

From the given energy levels :

So, the transition must be from E₅ to E₂. Hence, this is the required solution.
The total momentum of a system is the vector sum of all the individual masses that comprise the system.
Moreover, To calculate the total momentum of two objects during a collision, add their individual momentums. You can calculate the momentum for each object using the formula p=mv, where p is the momentum, m is the mass, and v is the velocity. The law of conservation of momentum can be expressed as follows. For a collision between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision.
You can learn more about this at:
brainly.com/question/20301772#SPJ4
In 2.34 hours, the bus travels 16.34 km.
Average speed = (distance covered) / (time to cover the distance).
Average speed = (16.34 km) / (2.34 hours) = 6.983 km/hr