Honors Physics E & M review
Electric Field:
- Definition: Electric field is a region around a charged object where a force would be experienced by other charged objects placed in that region.
- Explanation: It represents the force per unit charge experienced by a test charge at any point in space.
- Unit: Newton per coulomb (N/C)
Electric Potential Energy:
- Definition: Electric potential energy is the energy that a charge possesses due to its position in an electric field.
- Explanation: When work is done to move a charge against an electric field, it gains electric potential energy.
- Formula: \( U = \frac{k q_1 q_2}{r} \)
Electric Potential:
- Definition: Electric potential at a point in an electric field is the amount of work done to bring a unit positive charge from infinity to that point.
- Explanation: It represents the potential energy per unit charge.
- Unit: Volt (V)
Induction:
- Definition: Induction is the process of charging a neutral object by bringing a charged object near it without direct contact.
- Explanation: Charges in the neutral object redistribute due to the presence of the charged object, creating regions of positive and negative charges.
Conduction:
- Definition: Conduction is the process of charging an object by direct contact with another charged object.
- Explanation: Electrons transfer between objects until equilibrium is reached, resulting in both objects having the same charge.
Polarization:
- Definition: Polarization is the separation of charges within an object without transferring them.
- Explanation: When a charged object is brought near, it causes the electrons within the neutral object to rearrange, creating regions of positive and negative charges.
Friction:
- Definition: Frictional charging occurs when two different materials are rubbed together, transferring electrons from one material to the other.
- Explanation: This transfer of electrons leads to one material becoming positively charged and the other becoming negatively charged.
Nature of Images Formed in Concave vs Convex Mirrors and Lenses:
- Concave Mirrors and Lenses: Can form both real and virtual images depending on the object's position.
- Real images are formed when the object is located beyond the focal point.
- Virtual images are formed when the object is located between the mirror/lens and the focal point.
- Convex Mirrors and Lenses: Always form virtual images.
- These images are upright and smaller than the object.
Resonance:
- Definition: Resonance occurs when the frequency of an external force matches the natural frequency of an object, causing it to vibrate with increased amplitude.
- Explanation: Resonance amplifies vibrations, often leading to significant effects, such as in musical instruments or structural vibrations.
Inverted Wave:
- A wave is inverted when it undergoes a phase shift of \(180^\circ\), causing crests to become troughs and vice versa.
Snell's Law:
- Definition: Snell's Law describes the relationship between the angles of incidence and refraction when light passes from one medium to another.
- Formula: \( n_1 \sin(\theta_1) = n_2 \sin(\theta_2) \)
- Explanation: It governs how light bends as it enters a new medium with a different refractive index.
Total Internal Reflection:
- Definition: Total internal reflection occurs when light traveling from a medium with a higher refractive index to a medium with a lower refractive index is reflected back into the higher index medium.
- Explanation: It happens when the angle of incidence is greater than the critical angle.
Additive Colors and Light:
- Additive color mixing occurs when colored lights are combined.
- Primary colors for light are red, green, and blue (RGB).
- Mixing these colors at full intensity produces white light.
Color Subtraction to Pigments:
- Color subtraction occurs when pigments absorb certain wavelengths of light.
- Primary colors for pigments are cyan, magenta, and yellow (CMY).
- Mixing these pigments subtracts wavelengths, producing different colors.
Doppler Effect:
- Definition: The Doppler Effect is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source.
- Explanation: It causes the pitch of sound waves to change when a sound source or observer is in motion relative to each other.
Focal Point:
- Definition: The focal point is the point where light rays parallel to the principal axis converge (in a concave mirror or lens) or appear to diverge (in a convex lens).
- Explanation: It is the point where an image is formed or appears to be formed.
Certainly! Here's an elaboration including term definitions for all relevant vocabulary words, along with additional explanations for an eleventh-grade Honors Physics class:
Unit 1 (Part 1): Electric Fields and Electric Potential
1. Conductors and Insulators:
- Conductors: Materials that allow the free flow of electric charge. Electrons in conductors are loosely bound and can move easily.
- Insulators: Materials that do not allow the free flow of electric charge. Electrons in insulators are tightly bound to their atoms and do not move freely.
2. Charging Methods:
- Conduction: Transfer of charge through direct contact between objects.
- Induction: Redistribution of charges without direct contact by bringing a charged object near a neutral object.
- Polarization: Rearrangement of charges within an object without charge transfer when influenced by an external electric field.
3. Coulomb's Law:
- Formula: \( F = \frac{k |q_1 q_2|}{r^2} \)
- Coulomb's Law calculates the force between two point charges \(q_1\) and \(q_2\) separated by a distance \(r\).
4. Superposition Principle:
- States that the total electric force on a charge due to multiple charges is the vector sum of the forces exerted by each individual charge.
5. Electric Field:
- Electric field is a vector field that surrounds electric charges and exerts force on other charges.
- Unit: Newton per coulomb (N/C)
6. Electric Potential Energy:
- Energy a charge possesses due to its position in an electric field.
- Formula: \( U = \frac{k q_1 q_2}{r} \)
7. Electric Potential:
- Electric potential at a point in an electric field is the electric potential energy per unit charge.
- Measured in volts (V).
Unit 1 (Part 2): Circuits
1. Electric Current: Flow of electric charge in a circuit.
- Unit: Ampere (A)
2. Ohm's Law:
- Formula: \( V = IR \)
- Defines the relationship between voltage (V), current (I), and resistance (R) in a circuit.
3. Parallel and Series Circuits:
- Series Circuits: Components connected end-to-end, where the same current flows through each component.
- Parallel Circuits: Components connected across common points, where voltage across each component is the same.
4. Equivalent Resistance:
- Total resistance in a circuit when resistors are combined in series, parallel, or a combination of both.
Unit 2: Magnetism
1. Magnetic Fields: Fields generated by magnets, current-carrying wires, or changing electric fields.
- Transverse Wave: A wave in which the medium's displacement is perpendicular to the direction of wave propagation. Light waves are transverse.
- Longitudinal Wave: A wave in which the medium's displacement is parallel to the direction of wave propagation. Sound waves are longitudinal.
3. Virtual Image and Real Image:
- Virtual Image: Formed by the apparent intersection of light rays. Cannot be projected onto a screen.
- Real Image: Formed by the actual intersection of light rays. Can be projected onto a screen.
Unit 3: Simple Harmonic Motion, Waves, and Sound
1. Simple Harmonic Motion: Periodic motion where the restoring force is proportional to displacement.
2. Frequency: Number of oscillations per unit time.
3. Wavelength: Distance between two successive points in a wave with the same phase.
4. Amplitude: Maximum displacement of a wave from its equilibrium position.
Unit 4: Electromagnetic Waves, Light, and Optics
1. Reflection and Refraction:
- Reflection: Bouncing back of light waves when they encounter a surface.
- Refraction: Bending of light waves as they pass from one medium to another.
2. Mirrors and Lenses:
- Plane Mirror: Flat mirror that forms a virtual image with the same size as the object.
- Concave Mirror: Curves inward and can form real or virtual images depending on the object's position.
- Convex Mirror: Curves outward and forms only virtual images.
3. Color Mixing:
- Additive Color Mixing: Mixing colored light to produce different colors (e.g., RGB in TVs).
- Subtractive Color Mixing: Mixing pigments to absorb certain wavelengths of light (e.g., CMY in printers).
Periodic - motion repeated in equal intervals
Oscillatory - back and forth motion around a fixed position
Simple harmonic - repetitive movement back and forth
restoring force - brings object in motion back to equilibrium
Cycle - a change from down to up, up to down
Period(T; s) - time required for one complete cycle
Frequency(f; Hz) -
1 hertz is 1 cycle per second
Mechanical wave example: sound, water
Electromagnetic wave example: radio, light
Superposition - displacement when waves cross
Wave interference - when two waves meet while traveling
Nodes - points of no displacement b/c of destructive interference
Anti-nodes - Maximum displacement from constructive interference