Answer:
Explanation:
In order to solve this question we need to know that . Then we need to convert 4 minutes into seconds and cm into m. We can do that by multiplying the number of minutes by 60 (because there is 60 seconds in one minute) and dividing the number of cm by 100 (because there is 100 cm in one m). So.......
4min = 4 x 60s = 240s
300cm = 300/100 m = 3m
Now we know that distance = 300m, and that the time = 4min = 240s ⇒
⇒
Answer:
The correct answer is A
Explanation:
The question requires as well the attached image, so please see that below.
Coulomb's Law.
The electrical force can be understood by remembering Coulomb's Law, that describes the electrostatic force between two charged particles. If the particles have charges and
, are separated by a distance r and are at rest relative to each other, then its electrostatic force magnitude on particle 1 due particle 2 is given by:
Thus if we decrease the distance by half we have
So we get
Replacing we get
We can then multiply both numerator and denominator by 4 to get
So we have
Thus if we decrease the distance by half we get four times the force.
Then we can replace the second condition
So we get
which give us
Thus doubling one of the charges doubles the force.
So the answer is A.
