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Medical physics equations

The 14 equations the medical physics notes display, each with a link to the lesson that states it. Of the 14, the data booklet prints 8, 4 are yours to memorise and 2 carry no badge either way.

Year 13 · 4 lessons with equations.

The marks refer to the AQA 7408 data booklet. An equation it prints is marked as such, and one it leaves out is marked to learn. An equation with no mark has not been checked against that booklet, and some of these belong to the Edexcel, OCR or CIE specification rather than AQA’s, so check them against your own board’s data or formula booklet.

4 lessons

Ultrasound imaging

d=ct2d = \frac{ct}{2}NOT IN THE AQA DATA BOOKLET: LEARN IT
Z=ρcZ = \rho cIN THE AQA DATA BOOKLET
IrIi=(Z2-Z1)2(Z2+Z1)2\frac{I_{r}}{I_{i}} =\frac{(Z_{2} - Z_{1})^{2}}{(Z_{2} + Z_{1})^{2}}IN THE AQA DATA BOOKLET
I=I0e-μxI = I_{0}e^{-\mu x}
Δff=2vcosθc\frac{\Delta f}{f} = \frac{2v\,\cos\theta}{c}

The physics of diagnostic X-rays

Emax=eVE_{max} = eVNOT IN THE AQA DATA BOOKLET: LEARN IT
I=I0e-μxI = I_{0}e^{-\mu x}IN THE AQA DATA BOOKLET
μm=μρ\mu_{m} = \frac{\mu}{\rho}IN THE AQA DATA BOOKLET

The eye as an optical system

P=1fP = \frac{1}{f}IN THE AQA DATA BOOKLET
1u+1v=1f\frac{1}{u} + \frac{1}{v} = \frac{1}{f}IN THE AQA DATA BOOKLET
m=vum = \frac{v}{u}IN THE AQA DATA BOOKLET

Intensity, loudness and the decibel scale

I=PAI = \frac{P}{A}NOT IN THE AQA DATA BOOKLET: LEARN IT
intensity level=10logII0\text{intensity level} = 10\,\text{log}\frac{I}{I_{0}}IN THE AQA DATA BOOKLET
relative intensity level=10logI2I1\text{relative intensity level} = 10\,\text{log}\frac{I_{2}}{I_{1}}NOT IN THE AQA DATA BOOKLET: LEARN IT

Every equation in the library is indexed by unit on the equation index, and the medical physics notes are where these equations are derived and used. The 4 the booklet leaves out are on the equations to memorise, alongside the rest of the course.

Also: Turning points equations