Answer:
1) f= 8.6 GHz
2) t= 0.2 ms
Explanation:
1)
- Since microwaves are electromagnetic waves, they move at the same speed as the light in vacuum, i.e. 3*10⁸ m/s.
- There exists a fixed relationship between the frequency (f) , the wavelength (λ) and the propagation speed in any wave, as follows:
- Replacing by the givens, and solving for f, we get:
⇒ f = 8.6 Ghz (with two significative figures)
2)
- Assuming that the microwaves travel at a constant speed in a straight line (behaving like rays) , we can apply the definition of average velocity, as follows:
where v= c= speed of light in vacuum = 3*10⁸ m/s
d= distance between mountaintops = 52 km = 52*10³ m
⇒ t = 0.2 ms (with two significative figures)
Astronomers find white dwarfs that distinguish them from main sequence stars because white dwarfs get really hot, we can search for their ultraviolet radiation.
<h3>What is a white dwarf?</h3>
A white dwarf is a very hot star that radiated much energy in the form of ultraviolet radiation.
This UV radiation is initially very bright and then these stars become red with time.
In conclusion, Astronomers find white dwarfs they can search for their ultraviolet radiation.
Learn more about white dwarfs here:
brainly.com/question/19602278
#SPJ1
Answer:
5295.3 N
Explanation:
According to law of momentum conservation, the change in momentum of the ball shall be from the momentum generated by the batter force
mv + P = mV
P = mV - mv = m(V - v)
Since the velocity of the ball before and after is in opposite direction, one of them is negative
P = 0.14(44.8 - (-19.5)) = 9 kg m/s
Hence the force exerted to generate such momentum within 1.7ms (0.0017s) is
F = P/t = 9/0.0017 = 5295.3 N
Answer:
Tx not but mybe
Explanation:
for that reason its just trying to help
