Coulomb's Law...

With the amount of students who have been gone due to illness I wanted to post the video that we watched in Physics class on Wednesday, April 13th, that describes Coulomb's Law. At the beginning of section 18B we learned how a charge can be detected by using an electroscope and what type of charge that's induced. For a review of this concept watch this video:

An electroscope, however, cannot quantify the charge. This is where Coulomb's Law comes in to play. Please make a note of the equation associated with Coulomb's Law and how closely it resembles the law for Gravitational Force. This video from Bozeman Science will explain the law by using an atom's electrons and protons:

Now Electrostatic Force and Gravitational Force, though closely resembling each other in form, are in fact different. There are two differences noted which will key to know for the test on Friday, April 15th. Whereas Electrostatic Force is both a repelling and attracting force, Gravitational Force is simply an attracting force. Also, Electrostatic Force deals with the charges of the objects while the Gravitational Force deals with the masses of the objects.

You will also notice in Coulomb's equation that there are absolute value signs encasing the charges (q). Remember that this means the charges will always be positive.

As for the very last section under 17B, be sure to pay attention to the SI units for the electrostatic force. This will also be on the test. Please let me know if you have any questions!