Answer:
Explanation:
Argon to potassium ratio after 1 half life = 1:1
After 2 half lives = 75/25= 3:1
After 3 half lives = 87.5/12.5= 7:1
After 4 half lives = 93.75/6.25 = 15:1
After 5 half lives = 96.875/3.125 = 31/1
Mechanical and electrical
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:
When there is nearsightedness or myopia
Explanation:
As, in myopia the image is formed in front of the retina.
Which makes things looking at things near very easy, but looking at far away things very difficult.
So concave lens makes things look bigger, so therefore, it is used during myopia, to make things look bigger when they are far away
