<span>This
is because astronomers have discovered that
the Crab Nebula is 6500 light years from earth. This means it takes 6500 earth years
for light to get from the Crab Nebula to
earth. Therefore, if we are able to observe the
Crab Nebula and beyond it then it means that earth has been in existence for 6500 years and
over. </span>
The one that is false in this case is 3) All EMR can be seen. We cannot see EMR that is below visible light with the naked eye.
However with this question, one thing that I would like to point out is that EMR only travels at the speed of light when it is in a vacuum a.k.a. air. Otherwise it doesn't travel at the speed of light because it could be refracted.
Answer:
Electrons are negatively charged particles
The Answer: 55 N
Reason: Because they are pushing in the same direction, their force of N gets added.
1. 30 + 25 = 55