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| 184_notes:superposition [2021/01/28 21:14] – bartonmo | 184_notes:superposition [2021/05/17 22:37] – schram45 |
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| To simplify the situation, we will usually make some sort of assumption. For example, //__we often assume that the charge(s) are fixed in place__// (something is holding them at a particular location, but we don't care what that something is). Or //__we will assume that we are interested in a particular instant in time__// and examine what is happening for that situation (like taking a single frame from a movie or freezing time). | To simplify the situation, we will usually make some sort of assumption. For example, //__we often assume that the charge(s) are fixed in place__// (something is holding them at a particular location, but we don't care what that something is). Or //__we will assume that we are interested in a particular instant in time__// and examine what is happening for that situation (like taking a single frame from a movie or freezing time). |
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| === How useful is this assumption? === | ==== How useful is this assumption? ==== |
| [{{ 184_notes:dipole.png?150|Dipole representation - one positive and one negative charge, separated by a distance d}}] | [{{ 184_notes:dipole.png?150|Dipole representation - one positive and one negative charge, separated by a distance d}}] |
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| [{{ 184_notes:dipole_epoint.png?150|Electric field at a single point (Point P) due to a dipole}}] | [{{ 184_notes:dipole_epoint.png?150|Electric field at a single point (Point P) due to a dipole}}] |
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| [[184_notes:pc_efield|As you have learned]], the electric field from a single //positive charge// at any given point will point away from the charge, and the electric field at any given point from a //negative charge// will point toward the point charge. So what happens to the electric field when you have a positive charge next to a negative charge? The field at any point in space around the two charges will be given by a **net electric field**, which is the [[184_notes:math_review#vector_addition|vector addition]] of the electric field from the positive charge and the electric field from the negative charge. | [[184_notes:pc_efield|As you have learned]], the electric field from a single //positive charge// at any given point will point //away// from the charge, and the electric field at any given point from a //negative charge// will point //toward// the point charge. So what happens to the electric field when you have a positive charge next to a negative charge? The field at any point in space around the two charges will be given by a **net electric field**, which is the [[184_notes:math_review#vector_addition|vector addition]] of the electric field from the positive charge and the electric field from the negative charge. |
| $$\vec{E}_{net}=\vec{E}_{+}+\vec{E}_{-}$$ | $$\vec{E}_{net}=\vec{E}_{+}+\vec{E}_{-}$$ |
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| ==== Examples ==== | ==== Examples ==== |
| [[184_notes:examples:Week3_superposition_three_points|Superposition with Three Point Charges]] | Video Example: |
| | {{youtube>2VLMLuL2N7s?large}} |
| | Written out work: [[184_notes:examples:Week3_superposition_three_points|Superposition with Three Point Charges]] |
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| [[184_notes:examples:Week3_plotting_potential|Plotting Potential for Multiple Charges]] | [[184_notes:examples:Week3_plotting_potential|Plotting Potential for Multiple Charges]] |