Coulomb's Law Introduction

Open the Electrostatics Force Mini Lab http://www.thephysicsaviary.com/Physics/Programs/Labs/ForceElectricMiniLab/index.html in a side by side window (alt[ and alt]) This equation is called Coulomb's Law. Change the value of r. What does r measure?

• the distance between the two charged objects

• the amount of charge carried by the objects

• the amount of force between two charged objects

(On our equation sheet, we use d instead of r.) In this lab, r is measured in cm, which is common because a meter is so big on the the scale of charged objects. Still, though, the Standard International unit of distance is the

• meter

• inch

In this lab, what does Fe stand for?

• electrostatic Force

• the symbol for iron

What will be the units of F? (We can just call it F instead of Fe.)

• Newtons

• meters

• Coulombs

As the value of r increases, what happens to the value of F?

• F increases

• F decreases

• F never changes

Increase the value of one of the q's. As q increases, what happens to F?

• F increases

• F decreases

• F never changes

What does q measure?

• the distance between the two charged objects

• the amount of charge carried by the object

• the amount of force between two charged objects

Why are there two q's in the equation?

• because there are two objects

• because there are protons and electrons

in this lab, q is measured in nC, which is common because a Coulomb is actually a very large amount of charege, so we often see microCoulombs or nC - nanoCoulomb. Still, though, the Standard International unit of CHARGE is the

• Coulomb

• Newton

• Joule

• Watt

What can you do to increase the value of k?

• increase the Force

• increase the distance

• decrease the charge

• nothing can be done to change the value of k - it is a constant