When rounding you look at the number right after the one you want to round. The tenth place is the one right after the decimal. If the number after it is more than five it goes up by one, it it's less than five it stays the same. So since the number after the 8 is a 3 it stays the same.
The answer is 7.8
The magnitude of the electrical force between a pair of charged particles is 4 Times as much when the particles are moved half as far apart.
This can be easily understood by Columb's law,

which state's that the amount of electrical force experienced by two charged particles is inversely proportional to the square of the distance between them.
∴ 
Now, we know the new distance is half the original distance,


The electrical force of attraction or electrostatic force of attraction between two charged particles refers to the amount of attractive or repulsive force that exists between the two charges. This can be calculated by Columb's Law.
A charged particle in physics is a particle that has an electric charge. It might be an ion, such as a molecule or atom having an excess or shortage of electrons in comparison to protons. The same charge is thought to be shared by an electron, a proton, or another primary particle.
Learn more about electrical force here
brainly.com/question/2526815
#SPJ4
Answer:
An electrolytic cell converts electrical energy into chemical energy.
Explanation:
There’s not enough info here i’m sorry
Answer:
Time moves slower and length decreases.
Explanation: