No light does not need medium to travel.Its an electromagnetic(EM) wave.All EM waves travel independent of medium. In contrast mechanical waves need a medium,sound waves,shock waves are mechanical and they need medium to transfer energy or travel.
Well, st first we should find <span>initial momentum for the first person represented in the task which definitely must be :
</span>

And then we find the final one :

Then equate them together :
So we can get the velocity, which is

In that way, according to the main rules of <span>conservation of momentum you can easily find the solution for the second person.
Regards!</span>
Answer:
The rock will reach 9 m from the ground at eaxactly 5.06 s after it was initially thrown upwards.
Explanation:
We will use the equations of motion for this.
u = initial velocity of the rock = 22 m/s
g = acceleration due to gravity = -9.8 m/s²
y = vertical position of the rock at a time t = 9 m
y₀ = initial height of the rock = 25 m
t = time it takes for the rock to reach height of 9 m.
(y-y₀) = ut + 0.5gt²
(9 - 25) = 22t + 0.5(-9.8)t²
- 14 = 22t - 4.9t²
4.9t² - 22t - 14 = 0
solving this quadratic equation,
t = 5.055 s or - 0.565 s
Since time cannot be negative,
t = 5.055 s = 5.06 s
Hope this Helps!!!
In Electromagnetic spectrum, X-rays has very high frequency but gamma-rays has more than that. If you consider cosmic rays as an electromagnetic wave, then it would be highest energetic and has highest frequency.
In short, Your Answer is "Cosmic rays"
Hope this helps!
Answer:
A) t = 0.55 s
B) x = 24.8 m
Explanation:
A) We can find the time at which the ball will be in the air using the following equation:
Where:
is the final height= 0
is the initial height= 1.5 m
is the component of the initial speed in the vertical direction = 0 m/s
t: is the time =?
g: is the gravity = 9.81 m/s²

By solving the above equation for t we have:
Hence, the ball will stay 0.55 seconds in the air.
B) We can find the distance traveled by the ball as follows:

Where:
a: is the acceleration in the horizontal direction = 0
is the final position =?
is the initial position = 0
is the component of the initial speed in the horizontal direction = 45 m/s


Therefore, the ball will travel 24.8 meters.
I hope it helps you!