Answer:
a. Light pollution refers to light used for human activities that brightens the sky and hinders astronomical observations.
Explanation:
Light pollution is due to the excessive and misdirected use of artificial light. Light bulbs are often design in an incorrect way, since a great part of its light is not completely directed to the ground and an important percentage is emitted to the sky in where will be scattered and reflected back to ground by the particles in the atmosphere. That brings as an effect a sky glow, therefore the visibility of astronomical objects will be extremely reduce.
Hence, professional astronomical research and amateur observations will be affected. Light pollution has a negative impact on bird migration at night and in the health of difference species, humans also.
Answer:
20 degrees.
Explanation:
From Snell’s law of refraction:
sinθ1•n1 = sinθ2•n2
where θ1 is the incidence angle, θ2 is the refraction angle, n1 is the refraction index of light in medium1, and n2 is the refraction index for virgin olive oil. The incidence angle of the red light is θ1 = 30 degrees.
The red light is in air as medium1, so n1 (air) = 1.00029
So, to find θ2, the refracted angle:
sinθ1•1.00029 = sinθ2•1.464
sin(30)•1.00029 / 1.464 = sinθ2
0.5•1.00029 / 1.464 = sinθ2
sinθ2 = 0.3416291
θ2 = arcsin(0.3416291)
θ2 = 19.976 degrees
To the nearest degree,
θ2 = 20 degrees.
Answer:
160N
Explanation:
Moments must be conserved - so.
Answer:
T = 5.36 s
Explanation:
given,
depth of the mine shaft = 122.5 m
speed of the sound = 340 m/s
time taken = ?
time taken by the stone to reach at the bottom
using equation of motion
initial speed , u = 0 m/s
t = 5 s
time taken by the sound to travel
d =v x t
t = 0.36 s
total time taken for the sound to reach carol after dropping the stone
T = 5 + 0.36
T = 5.36 s