AP Physics 2 Equations Flashcards

Electricity and Magnetism Overview

• Covers fundamental principles involving electric charges and magnetic fields.
• Essential for understanding various physical phenomena and applications in technology.

Coulomb's Law Constant

• Defined as ( k = ¼∏ε₀ = 9.0 \times 10⁹ , \text{Nm}²/\text{C}² ).
• Represents the strength of the electrostatic force between charged objects.

Electric Force Equation

• Given by ( F = \frac{(¼∏ε₀)(q₁q₂)}{r²} = k \frac{(q₁q₂)}{r²} ).
• Describes the force between two point charges based on their magnitudes and distance.

Force in Electric Fields

• Expressed as ( F = qE ).
• Indicates the force acting on a charged particle within an electric field, where ( E ) is the electric field strength.

Electric Potential Energy

• Calculated using ( U(e) = qV = \frac{(¼∏ε₀)(q₁q₂)}{r} ).
• Represents energy associated with local electric field configurations.

Electric Field Strength

• Average electric field between parallel plates is given by ( E(avg) = -\frac{V}{d} ).
• Highlights the relationship between voltage and distance in defining the electric field.

Voltage from Point Charges

• Described by ( V = \frac{(¼∏ε₀)}{\sum q(i)/r(i)} ).
• Represents the electrical potential created by point charges at a distance.

Capacitor Charge-Voltage Relationship

• Defined by ( C = \frac{Q}{V} ).
• Illustrates the proportionality between stored charge ( Q ) and voltage ( V ).

Parallel-Plate Capacitance Formula

• Given as ( C = \frac{ε₀A}{d} ).
• Relates capacitance ( C ) to the area of plates ( A ) and separation ( d ).

Potential Energy in Capacitors

• Calculated using ( U(c) = \frac{1}{2}QV = \frac{1}{2}CV² ).
• Represents energy stored in a capacitor based on its charge and voltage.

Current Equation

• Defined as ( I(avg) = \frac{ΔQ}{Δt} ).
• Indicates the flow of charge over time, central to electrical circuit analysis.

Resistance of a Material

• Expressed as ( R = \frac{ρL}{A} ).
• Depicts the relationship between material resistivity ( ρ ), length ( L ), and cross-sectional area ( A ).

Voltage across a Resistor

• Given by ( V = IR ).
• Relates voltage ( V ) to current ( I ) and resistance ( R ) in circuits.

Power in Electrical Systems

• Equations include ( P = IV, P = \frac{V²}{R}, P = I²R ).
• These formulas indicate the rate of energy transfer in electrical components.

Capacitance in Parallel

• Total capacitance given by ( C(p) = ∑C(i) ).
• Indicates that capacitances in parallel add directly.

Capacitance in Series

• Total capacitance calculated using ( \frac{1}{C(s)} = ∑\frac{1}{C(i)} ).
• Reflected as the reciprocal of the sum of reciprocals of individual capacitances.

Resistance in Series

• Summed up by ( R(s) = ∑R(i) ).
• Resistors in series increase total resistance linearly.

Resistance in Parallel

• Calculated with ( \frac{1}{R(p)} = ∑\frac{1}{R(i)} ).
• Total resistance is less than the smallest individual resistor in the network.

Magnetic Force on Charged Particles

• Determined by ( F = qvB \sinθ ).
• Describes the force experienced by a charge moving in a magnetic field at an angle.

Magnetic Force on Current-Carrying Wire

• Given by ( F = BIℓ \sinθ ).
• Indicates the force on a straight wire carrying current ( I ) within a magnetic field.

Magnetic Field from Current

• Explained with ( B = \frac{μ₀}{2∏} \frac{I}{r} ).
• Shows the relationship between current and the generated magnetic field at a distance ( r ).

Magnetic Flux

• Defined by the equation ( Θ(m) = BA \cosθ ).
• Represents the amount of magnetic field passing through a given area.

Induced EMF in Loops

• Calculated as ( ε(avg) = -\frac{ΔΘ}{Δt} ).
• Relates changes in magnetic flux over time to induced electromotive force.

Induced EMF in Rectangular Wire

• Expressed by ( ε = Bℓv ).
• Depicts the induced EMF in a wire moving through a magnetic field with velocity ( v ).