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.
When ice melts, its temperature doesn't change ... ice at 32 degrees becomes water at 32 degrees.
When water boils, its temperature doesn't change ... water at 212 degrees becomes steam at 212 degrees.
The row that says both of these is row-D .
1. Law 1, since there is no other force acting on your body as you stand there, so you will continue to go forward.
2. Law 3, since the swimmer is using opposite forces to propel herself through the water. She generates a force by pushing the water which helps to push her forward.
3. Law 2, since you are giving the motorcycle more energy as a result of the gas being transformed into the energy that helps to accelerate the motorcycle's speed.
Answer:
220 V
Explanation:

As the resistors are connected in series,

= 20 + 30 + 60
= 110 ohms
V = IR
= 2 * 110
= 220 V
Hope it helps