Chapter 17. Coulomb’s law (16-1)

Question

GlyjYdcNntTwxk6eNCNnUEoVzqpmDS5rFnscftFwZ10DzvXd1IlqnOPaGk9eGYLfRiQ8++X//7ZXMAee8WLBquOYOSR4WWmAPOy7NGvcnj+pBKnZPlK4iTk+VmbNQm8Bs53f3g==
{"title":"Any two point charges q sub 1 and q sub 2 exert equally strong electric forces on each other.","description":"Correct!","type":"correct","color":"#99CCFF","code":"[{\"shape\":\"poly\",\"coords\":\"82,133\"},{\"shape\":\"rect\",\"coords\":\"10,16,12,16\"},{\"shape\":\"poly\",\"coords\":\"144,22\"},{\"shape\":\"rect\",\"coords\":\"2,21,17,45\"},{\"shape\":\"rect\",\"coords\":\"104,21,122,44\"}]"} {"title":"Coulomb constant","description":"Wrong","type":"incorrect","color":"#ffcc00","code":"[{\"shape\":\"rect\",\"coords\":\"210,2,228,29\"}]"} {"title":"Absolute values of the point charges","description":"Incorrect","type":"incorrect","color":"#333300","code":"[{\"shape\":\"rect\",\"coords\":\"227,24,228,24\"},{\"shape\":\"rect\",\"coords\":\"233,6,249,32\"},{\"shape\":\"rect\",\"coords\":\"267,5,285,29\"}]"} {"title":"Distance between the point charges","description":"Incorrect","type":"incorrect","color":"#000080","code":"[{\"shape\":\"rect\",\"coords\":\"242,45,262,64\"}]"}

Question

O/vKXcQmzlU6zTGNJD/cTVj80sI=
{"title":"Any two point charges q sub 1 and q sub 2 exert equally strong electric forces on each other.","description":"Wrong","type":"incorrect","color":"#99CCFF","code":"[{\"shape\":\"poly\",\"coords\":\"82,133\"},{\"shape\":\"rect\",\"coords\":\"10,16,12,16\"},{\"shape\":\"poly\",\"coords\":\"144,22\"},{\"shape\":\"rect\",\"coords\":\"2,21,17,45\"},{\"shape\":\"rect\",\"coords\":\"104,21,122,44\"}]"} {"title":"Coulomb constant","description":"Correct!","type":"correct","color":"#ffcc00","code":"[{\"shape\":\"rect\",\"coords\":\"210,2,228,29\"}]"} {"title":"Absolute values of the point charges","description":"Incorrect","type":"incorrect","color":"#333300","code":"[{\"shape\":\"rect\",\"coords\":\"227,24,228,24\"},{\"shape\":\"rect\",\"coords\":\"233,6,249,32\"},{\"shape\":\"rect\",\"coords\":\"267,5,285,29\"}]"} {"title":"Distance between the point charges","description":"Incorrect","type":"incorrect","color":"#000080","code":"[{\"shape\":\"rect\",\"coords\":\"242,45,262,64\"}]"}

Question

QJIB+qAShen3X6uLv1B1Fhe7/fLbfSKgwqy/EjrlxZgFy2bkbCAy9w==
{"title":"Any two point charges q sub 1 and q sub 2 exert equally strong electric forces on each other.","description":"Wrong","type":"incorrect","color":"#99CCFF","code":"[{\"shape\":\"poly\",\"coords\":\"82,133\"},{\"shape\":\"rect\",\"coords\":\"10,16,12,16\"},{\"shape\":\"poly\",\"coords\":\"144,22\"},{\"shape\":\"rect\",\"coords\":\"2,21,17,45\"},{\"shape\":\"rect\",\"coords\":\"104,21,122,44\"}]"} {"title":"Coulomb constant","description":"Wrong","type":"incorrect","color":"#ffcc00","code":"[{\"shape\":\"rect\",\"coords\":\"210,2,228,29\"}]"} {"title":"Absolute values of the point charges","description":"Correct!","type":"correct","color":"#333300","code":"[{\"shape\":\"rect\",\"coords\":\"227,24,228,24\"},{\"shape\":\"rect\",\"coords\":\"233,6,249,32\"},{\"shape\":\"rect\",\"coords\":\"267,5,285,29\"}]"} {"title":"Distance between the point charges","description":"Incorrect","type":"incorrect","color":"#000080","code":"[{\"shape\":\"rect\",\"coords\":\"242,45,262,64\"}]"}

Question

F7nQFApL+MYYvO7+lYY//dl2GULunnvnXbeZmRyZjSSPiK6Pes4/Ng==
{"title":"Any two point charges q sub 1 and q sub 2 exert equally strong electric forces on each other.","description":"Wrong","type":"incorrect","color":"#99CCFF","code":"[{\"shape\":\"poly\",\"coords\":\"82,133\"},{\"shape\":\"rect\",\"coords\":\"10,16,12,16\"},{\"shape\":\"poly\",\"coords\":\"144,22\"},{\"shape\":\"rect\",\"coords\":\"2,21,17,45\"},{\"shape\":\"rect\",\"coords\":\"104,21,122,44\"}]"} {"title":"Coulomb constant","description":"Wrong","type":"incorrect","color":"#ffcc00","code":"[{\"shape\":\"rect\",\"coords\":\"210,2,228,29\"}]"} {"title":"Absolute values of the point charges","description":"Incorrect","type":"incorrect","color":"#333300","code":"[{\"shape\":\"rect\",\"coords\":\"227,24,228,24\"},{\"shape\":\"rect\",\"coords\":\"233,6,249,32\"},{\"shape\":\"rect\",\"coords\":\"267,5,285,29\"}]"} {"title":"Distance between the point charges","description":"Correct!","type":"correct","color":"#000080","code":"[{\"shape\":\"rect\",\"coords\":\"242,45,262,64\"}]"}

Review

If we replace \(m\) and \(G\) in Equation 10-2 with \(q\) and \(k\), we see that Equation 16-1 is identical to Equation 10-2 for the gravitational force, but with an important difference: The electric force is attractive (like the gravitational force) if the two charges \(q_1\) and \(q_2\) have opposite signs (one negative and the other positive), but repulsive if \(q_1\) and \(q_2\) have the same sign (either both positive or both negative).