From 06084e083f8c5111f8fc0179023797eb3315c0b3 Mon Sep 17 00:00:00 2001 From: Andrew Lorimer Date: Wed, 22 Aug 2018 09:27:23 +1000 Subject: [PATCH] update methods / physics / spec notes --- methods/calculus.md | 5 +++++ physics/light-matter.md | 30 ++++++++++++++++++++++++++++++ spec/calculus.md | 21 ++++++++++++++------- 3 files changed, 49 insertions(+), 7 deletions(-) diff --git a/methods/calculus.md b/methods/calculus.md index 8cb3521..fb3761f 100644 --- a/methods/calculus.md +++ b/methods/calculus.md @@ -72,3 +72,8 @@ Normal line for point $P(q,r)$ on function $f$ is $y=mx+c$ where $m={-1 \over m_ **In main**: type function. Interactive -> Calculation -> Line -> (Normal | Tan line) **In graph**: define function. Analysis -> Sketch -> (Normal | Tan line). Type $x$ value to solve for a point. Return to show equation for line. + +## Stationary points + +Stationary where $m=0$. +Find derivative, solve for ${dy \over dx} = 0$ diff --git a/physics/light-matter.md b/physics/light-matter.md index fd6828c..a44f583 100644 --- a/physics/light-matter.md +++ b/physics/light-matter.md @@ -32,11 +32,13 @@ $$ 1 \operatorname{eV} = 1.6 \times 10^{-19} \operatorname{J}$$ #### Wave / particle (quantum) models wave model: + - cannot explain photoelectric effect - $f$ is irrelevant to photocurrent - predicts that there should be a delay between incidence of radiation and ejection of e- particle model: + - explains photoelectric effect - rate of photoelectron release is proportional to intensity of incident light - shining light on a metal "bombards" it with photons @@ -117,6 +119,34 @@ Particle model allows potential for photons to interact as they pass through sli ## Quantum mechanics +- uncertainty occurs in any measurement +- inherent physical limit to absolute accuracy of measurements (result of wave-particle duality) +- interaction between observer and object +- measuring location of an e- requires hitting it with a photon, but this causes $\rho$ to be transferred to electron, moving it + +### Indeterminancy principle + +$$\sigma E \sigma t \ge {h \over 4 \pi}$$ + +where $\sigma n$ is the uncertainty of $n$ + +**$\sigma E$ and $\sigma t$ are inversely proportional$** + +Therefore, position and velocity cannot simultaneously be known with 100% certainty. + +### Single-slit diffraction + +- one photon passes through slit at any time (controlled by intensity) +- diffraction pattern can be explained by wave front split into wavelets +- diffraction can be represented as uncertainty of photonic momentum + + +### Comparison with Bohr's model + +**Newtonian (deterministic) model** - current $x$ and $v$ are known, so future $x$ can be calculated + +**Quantum mechanical model** - electron clouds rather than discrete shells (electrons are not particlces). We can only calculate probability of an electron being observed at a particular position + 774 abc melbourne \ No newline at end of file diff --git a/spec/calculus.md b/spec/calculus.md index 3823f37..a5f3346 100644 --- a/spec/calculus.md +++ b/spec/calculus.md @@ -95,11 +95,8 @@ $$\lim_{h \rightarrow 0} {{e^h-1} \over h}=1$$ ## Chain rule for $(f\circ g)$ -$$(f \circ g)^\prime = (f^\prime \circ g) \cdot g^\prime$$ - -Leibniz notation: - $${dy \over dx} = {dy \over du} \cdot {du \over dx}$$ +$${d((ax+b)^n) \over dx} = {d(ax+b) \over dx} \cdot n \cdot (ax+b)^{n-1}$$ Function notation: @@ -143,17 +140,22 @@ $\log_b (xy)=\log_b x + \log_b y$ $\log_b x^n = n \log_b x$ $\log_b y^{x^n} = x^n \log_b y$ +### Index identities +$b^{m+n}=b^m \cdot b^n$ +$(b^m)^n=b^{m \cdot n}$ +$(b \cdot c)^n = b^n \cdot c^n$ + ### $e$ as a logarithm $$\operatorname{if} y=e^x, \quad \operatorname{then} x=\log_e y$$ $$\ln x = \log_e x$$ ### Differentiating logarithms -$${d(\log_e x)\over dx} = x^-1 = {1 \over x}$$ +$${d(\log_e x)\over dx} = x^{-1} = {1 \over x}$$ -## Solving $e^x$ +## Solving $e^x$ etc -| $f(x)$ | $f^\prime(x)$ | +| $f(x)$ | $f^\prime(x)$ |xs | ------ | ------------- | | $\sin x$ | $\cos x$ | | $\sin ax$ | $a\cos ax$ | @@ -161,6 +163,11 @@ $${d(\log_e x)\over dx} = x^-1 = {1 \over x}$$ | $\cos ax$ | $-a \sin ax$ | | $e^x$ | $e^x$ | | $e^{ax}$ | $ae^{ax}$ | +| $ax^{nx}$ | $an \cdot e^{nx}$ | | $\log_e x$ | $1 \over x$ | | $\log_e {ax}$ | $1 \over x$ | +| $\log_e f(x)$ | $f^\prime (x) \over f(x)$ | +| $\sin(f(x))$ | $f^\prime(x) \cdot \cos(f(x))$ | + + -- 2.49.0