Thiết bị không phải nguồn điện:
Đáp án D
<span>The force would double.</span>
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
15 km 30 divided by 4 is 7.5 km in 30 min times that by 2 the answer is 15
A- hypothesis
You usually write hypothesis in science it’s something that can usually be tested.
B- prediction
Made before you do an science experiment, they’re usually like what you think could happen or will happen.
C- theory
Theses aren’t used with scientific evidence, they’re usually things that people believe happened. Example: Some believe Big Foot is real. But no one will ever know because its a theory
D- is already been eliminated, not all are right.
Answer is A
Hope this helped :)