Answer:Transformer
Explanation:All the other devices generate their own electricity apart from power line and Transformer, power line just carries electricity. A transformer can be used to step up or step down voltages from a source.
No option is correct as 1 is due to radiation
2. convection
3. conduction
A 5kg backpack will weigh 49 newtons on earth
Answer:
The diagram shows refraction, and medium 1 is less dense than medium 2.
Explanation:
- Reflection occurs when a light ray hits a surface and bounces back into the same medium
- Refraction occurs when a light ray crosses the interface between two different mediums, changing direction
From the diagram, we clearly see that this is a case of refraction, since the light ray crosses the boundary between two mediums.
The direction of a light ray in refraction is given by Snell's Law:
(1)
where
n1 and n2 are the index of refraction of the two mediums: a higher index of refraction means a higher density for the medium
are the angles of the light ray in medium 1 and medium 2, measured with respect to the normal to the interface
We can rewrite eq. (1) as
From the diagram, we see that
so
and so
which means
so, medium 2 is denser than medium 1, and the correct answer is
The diagram shows refraction, and medium 1 is less dense than medium 2.
Answer:
Doppler effect to analyze the motion and properties of the star and planet.
Explanation:
The radial velocity method invovles watching the spectral lines of a star as a planet orbits around the star. Because of the planets gravitational pull on the star, will wobble. This causes Doppler shifts in the spectral lines, allowing astronomers to infer the presence of the planets.