La velocidad correcta de la luz en el vacío es 300.000 km/s .
La distancia = (velocidad) x (duración de tiempo)
Duración de tiempo = 494 segundos, porque cada minuto = 60 segundos
La distancia = (300.000 km/s) x (494 s)
<em>La distancia = 148.200.000 km</em>
Answer:

Explanation:
Given:
- wavelength of light in the air,

- time taken to travel from the source to the photocell via air,

- time taken to reach the photocell via air and glass slab,

- thickness of the glass slab,

<u>Now we have the relation for time:</u>

hence,

c= speed of light in air



For the case when glass slab is inserted between the path of light:
(since light travel with the speed c only in the air)
here:
v = speed of light in the glass


Using Snell's law:



-- Although it's not explicitly stated in the question,we have to assume that
the surface is frictionless. I guess that's what "smooth" means.
-- The total mass of both blocks is (1.5 + 0.93) = 2.43 kg. Since they're
connected to each other (by the string), 2.43 kg is the mass you're pulling.
-- Your force is 6.4 N.
Acceleration = (force)/(mass) = 6.4/2.43 m/s²<em>
</em> That's about <em>2.634 m/s²</em> <em>
</em>(I'm going to keep the fraction form handy, because the acceleration has to be
used for the next part of the question, so we'll need it as accurate as possible.)
-- Both blocks accelerate at the same rate. So the force on the rear block (m₂) is
Force = (mass) x (acceleration) = (0.93) x (6.4/2.43) = <em>2.45 N</em>.
That's the force that's accelerating the little block, so that must be the tension
in the string.
Answer: Radiation
Explanation: Radiation is the energy that comes from a source in form of electromagnetic waves, subatomic particles, light, or heat which travels through space.
Examples of radiation include the light, heat, and particles emitted from the Sun.
Using a foil barrier to prevent heat transfer is possible because foil has a silver color, and silver reflects light and heat instead of absorbing them. This is the opposite of black surfaces that absorb heat.
So in homes where these foil reflective barriers are used, the transfer of heat through Radiation is highly reduced.
Answer:
they are used in periscopes,for signalling,in kaleidoscopes,to see round dangerous bends
Explanation: