diff --git a/Grade 10/Science/SNC2DZ/Unit 3: Physics.md b/Grade 10/Science/SNC2DZ/Unit 3: Physics.md new file mode 100644 index 0000000..aabf3e8 --- /dev/null +++ b/Grade 10/Science/SNC2DZ/Unit 3: Physics.md @@ -0,0 +1,124 @@ +# Unit 3: Physics + +## Light + - `Light`: Electromagnetic radiation/waves, as light interacts with both electricity and magnets + - Light travels at ~**3.0*108<\sup>** + - `Energy`: Ability to do work + - `Work`: Ability to move matter in space + - Energy can be transferred and transformed, but not destroyed + - Light behaves as a particle and/or a wave + - Behaves as particle when travelling through a vacuum, which waves cannot do + - Behaves as wave by forming "interference patterns", properties of light waves are also measurable + - `Photon`: Light particle + +### Properties of electromagnetic waves + + + - `Amplitude`: Height from centre to crest/trough + - `Crest`: Peak of wave + - `Trough`: Base of wave + - `Wavelength`: Distance between two points on wave on the same plane + - `Frequency`: Waves passing per (e.g., hertz (waves per second)) + - Visible light wavelengths are between 400-700 nm long + + + + - Light always travels in a straight line + - **Longer** wavelength = **smaller** frequency = **less** energy + - **Shorter** wavelength = **higher** frequency = **more** energy + - **Higher** energy, **lower** penetration (e.g., 2.4 GHz vs 5 GHz Wi-Fi) + - `Luminous`: Emits light + - Non-luminous objects do not emit light + - `Colour`: Reflected parts of white light from non-luminous objects + - Blacks absorb all visible light while whites do the opposite + +### Luminescence + - Things that emit light fill in here plz thanks + +### Rays + - Light path can be tracked via arrrows + - `Normal`: Perpendicular line to an interface (e.g., mirror, medium boundary), intersecting where light reflects off + - `Angle of incidence`: Angle of light hitting reflective surface, relative to the normal + - `Angle of reflection`: Angle of light leaving reflective surface, relative to the normal + - Laws of reflection + - Angle of incidence = angle of reflection + - Light rays are on the same plane + - Types of reflection + - `Specular reflection`: All normals are parallel (e.g., reflection off mirror) + - `Diffuse reflection`: Not all normals are parallel (e.g., paper, not-mirrors) + +## Mirrors + - A mininum of **two** incident rays are required to find an image + - Where rays converge describe image + - **Dotted** lines are used for light going beyond a mirror (as light does not actually travel there) + - `SALT`: Describes image + - `Size`: Relative to object + - `Attitude`: Orientation relative to object + - `Location`: Relative to mirror and/or object + - `Type`: Virtual (behind mirror) or real (in front of mirror) + +### Plane mirrors + + + + - `Object-image line`: Line perpendicular to plane mirror + - Distance is equal on both sides of mirror + - Describes location of object without requiring 2+ incident rays + - Banned + +### Concave and convex mirrors + - `Concave mirror`: Curved mirror curving inwards in the direction of incident rays, like a cave + - `Convex mirror`: Curved mirror curving away from incident rays, like back of a spoon + + + + - `Principal axis`: $`PA`$, line perpendicular to mirror when it hits it + - `Centre of curvature`: $`C`$, point where the centre of the circle would be if mirror was extended to a full circle + - `Focus`: $`F`$, point where all light rays focus on if incident rays are parallel to principal axis + - `Vertex`: $`V`$, point where principal axis meets mirror + - Imaging rules for curved mirrors: + - 1. Any incident ray **parallel** to the principal axis will reflect directly to or away from the **focus** + - 2. Any incident ray that would pass through the **focus** will reflect **parallel** to the principal axis + - 3. Any incident ray that would pass through the **centre** of curvature will reflect **back on the same path** + - 4. Any incident ray that reflects off the **vertex** reflect as if it were a plane mirror + +**Characteristics of concave mirror images** + +| **Object location** | **Size** | **Attitude** | **Location** | **Type** | +| :--- | :--- | :--- | :--- | :--- | +| Farther than C | Smaller than object | Inverted | Between C and F | Real | +| At C | Same as object | Inverted | On C | Real | +| Between C and F | Larger than object | Inverted | Farther than C | Real | +| At F | N/A, lines do not converge | | | | +| Between F and V | Larger than object | Upright | Behind mirror | Virtual | + +**Characteristics of convex mirror images** + +| **Object location** | **Size** | **Attitude** | **Location** | **Type** | +| :--- | :--- | :--- | :--- | :--- | +| Anywhere | Smaller than object | Upright | Between F and V/behind mirror | Virtual | + +## Refraction + - Speed of light depends on its medium + - Light bending while transitioning from a slower to faster medium or vice versa + - Greater the change in speed, greater than change in direction + - Turns in direction of **leading edge** + - Analogy: Sleds slowing from one runner first when transitioning from snow to pavement + - **Slow -> fast** medium: Refracts **away** from normal + - **Fast -> slow** medium: Refracts **towards** normal + - `Angle of refraction`: Angle of light after interface, relative to normal + - Index of refraction: speed of light in vacuum / speed of light in medium + - $`n = \frac{c}{v}`$ + - $`n_{1}sin\theta_{incidence} = n_{2}sin\theta_{refraction}`$ + - Where $`n_{1}`$ and $`n_{2}`$ are the refractive indexes of two different media + - Snell's law: $`\frac{sin\theta_{2}}{sin\theta_{1}} = \frac{v_{2}}{v_{1}} = \frac{n_{1}}{n_}2} + +## Total internal reflection + - `Critical angle`: Angle of incidence that causes refracted ray to be perpendicular to normal + - TIR occurs when angle of incidence exceeds critical angle, causing near-100% reflection + - Happens only when refracting from **slow to fast** + - **Refraction is not perfect; some light is reflected during refraction** + - Reflected ray grows brighter as we reach critical angle, and refracted ray grows dimmer + - **Higher** index of refraction = **lower** critical angle + + \ No newline at end of file