All AP Physics 1 Resources
Example Questions
Example Question #11 : Electric Force Between Point Charges
Two electric charges are placed apart, where and .
What is the magnitude of force between them? Is it replusive or attractive?
The force between the two charged particles is proportional to the product of their charges, according to Coulomb's Law. Whether the force is attractive or repulsive depends on the signs of the charges. Like signs will repel while opposite signs will attract.
Using Coulomb's Law to find the magnitude of the charge:
Therefore, the magnitude of the force has been discovered. Finally, since the signs are opposite ( and ), the force is attractive. Therefore the answer is:
Example Question #12 : Electric Force Between Point Charges
Which of the following pairs of charges would exhibit the most electrostatic repulsive force?
charge and charge apart
charge and charge apart
charge and charge apart
charge and charge apart
charge and charge apart
charge and charge apart
The correct answer is the charge and charge apart.
This results in the largest repulsive force according to the following equation:
is the repulsive force, is the magnitude of the charge, is the distance between the charges and is Coulomb's constant.
and charges placed apart provides the greatest repulsive force.
Certified Tutor