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)
Answer:
O C. Light energy
Explanation:
it conducts energy in it and is an energy itself.
It brings together combinations of product
Answer:
1830 m /s
Explanation:
The potential energy of the projectile at the surface of planet
- G x 1.46 x 10²³ m / 5 x 10⁶
Kinetic energy at surface
1/2 m v²
Total energy = - G x 1.46 x 10²³ m / 5 x 10⁶ + 1/2 m v²
- 6.67 X 10⁻¹¹ x 1.46 x 10²³ /5 x 10⁶ m + 1/2 m x 2000²
- 1.947 x 10⁶ m + 2m x 10⁶
= .053 x 10⁶ m
Potential energy of projectile at 1000 km height
= - G x 1.46 x 10²³ m / 6 x 10⁶
= - 1.6225 x 10⁶ m J
Total energy
= - 1.6225 x 10⁶ + 1/2 m V ²
Applying conservation of energy in gravitational field at surface and height
- 1.6225 x 10⁶ m + 1/2 m V ² = .053 x 10⁶ m
1/2 V ² = ( .053 + 1.6225 ) x 10⁶
1/2 V² = 1.6755 x 10⁶ m /s
V = 1.83 X 10³ m/s
1830 m /s
The best answer is Curve 1, since the majority of its brightness-wavelength spectrum is of low brightness and closer to yellow-orange-red. We can also assume a relatively low temperature, which red stars, especially red dwarves, demonstrate as well.