|
Title: how do I use Coulomb's Law to find an unknown force between particles? Post by: nyno2010 on Sep 22, 2012 its on my study guide.
-Use Coulomb's Law to find an unknown force between particles. Know whether the particles attract or repel and how changing the distance between charges affects the force. ^I've missed a lot of class lately and so I'm just confused. explain please? THANK YOUU! Title: how do I use Coulomb's Law to find an unknown force between particles? Post by: nynkh on Sep 22, 2012 Content hidden
Title: how do I use Coulomb's Law to find an unknown force between particles? Post by: micmac63 on Sep 22, 2012 Coulomb's Law is easy. It is
F = -KQq/r^2 where f is the force, K is the electrostatic constant (8.99 x 10^9 Nm^2/C^2), Q and q are two point charges, and r is the distance between them. Q and q can be positive or negative. If they have the same sign, the electrostatic force between them is repulsive. If they have opposite signs, the force is attractive. Fundamentally, Coulomb's Law is an inverse-square law (1/r^2 or r^-2), so at twice the distance from each other (than some arbitrary reference distance) the magnitude of the force is 1/4 as strong, at 3x the distance the force is 1/9th as strong, at 4x it's 1/16th, and so on. Importantly, sometimes Coulomb's Law is written as F = -(Qq) / (4(pi)(epsilon0)r^2), where epsilon0 (I dunno how to put Greek letters on this otherwise I would) is the permittivity constant and is 8.85 x 10^-12 C^2/Nm^2. |