1. P3 REVISION – CHAPTER 1 – MEDICAL APPLICATIONS OF PHYSICS
X-rays:
Explain what an x-ray is:
Describe some of the safety issues with X-rays:
Describe what a CT scanner is:
Ultrasound:
Describe how an ultrasound works:
Explain how an ultrasound can be used to measure distance:
Explain some of the therapeutic uses of ultra sound:
Lenses:
Describe how a convergent lens works:
Describe how a divergent lens works:
Describe how the lens works in the eye:
Endoscope:
Describe how an endoscope works:
Describe how we use endoscopes in medicine:
Refraction index:
The refractive index of the substance, 𝑛= sin 𝑖 sin 𝑟
Where 𝑖 is the angle of incidence and 𝑟 is the angle of refraction.
KEY WORDS:
Radiograph
Refraction index
Charge-couple device
Endoscope
Converging lens
CT scanner
Diverging lens
Transducer
Principal focus
A-scan
Magnifying
Refraction
Focal length
Snell’s law
Image
ASSESSMENT:

2. P3 REVISION – CHAPTER 2 – USING PHYSICS TO MAKE THINGS WORK
Moments:
Describe what a moment it:
Complete the equation:
Moment = ____ X perpendicular distance
from the line of the force
to the pivot
______ newtons ________
______
Nm m
Moments in balance:
When a see-saw is balanced:
the anticlockwise moment due to W1 about the pivot = W1d1
the clockwise moment due to W2 about the pivot = W2d2
Calculate W1, if W2 = 7.0N, d1 = 0.40m and d2 = 0.25m
Circular motion:
Explain centripetal force and the factors that affect it:
Centre of mass:
Describe what the centre of mass of an object is:
Draw the centre of mass on these shapes:
Stability:
Explain the following:
Tractor safety:
Bus tests:
High chairs:
The pendulum:
Describe the motion of a pendulum:
The frequency of the oscillations is the number of complete cycles of oscillation per second.
the time period = 1 𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 𝑜𝑓 𝑡ℎ𝑒 𝑜𝑠𝑐𝑖𝑙𝑙𝑎𝑡𝑖𝑜𝑛𝑠 (𝑖𝑛 ℎ𝑒𝑟𝑡𝑧, 𝐻𝑧)
(in seconds, s)
Hydraulics:
Describe how machines use hydraulics:
The formula for pressure is:
Pressure (Pa or N/m2) = 𝑓𝑜𝑟𝑐𝑒 (𝑁) 𝑎𝑟𝑒𝑎 ( 𝑚 2 )
KEY WORDS:
Load
Pressure
Effort
Pascal (Pa)
Pivot
Hydraulic Centripetal
Line of action
Centre of mass
Oscillation
Equilibrium
Amplitude
Moments
Frequncy
Resultant
ASSESSMENT:

3. P3 REVISION – CHAPTER 3 – USING MAGNETIC FIELDS TO KEEP THINGS MOVING
Explain how an electromagnet works:
Explain Fleming’s left hand rule:
Explain how an electric motor works:
Explain electromagnetic induction:
Explain how a transformer works:
The transformer equation is:
𝑝𝑑 𝑎𝑐𝑟𝑜𝑠𝑠 𝑝𝑟𝑖𝑚𝑎𝑟𝑦, 𝑉 𝑃 𝑝𝑑 𝑎𝑟𝑜𝑠𝑠 𝑠𝑒𝑐𝑜𝑛𝑑𝑎𝑟𝑦, 𝑉 𝑆 = 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑢𝑟𝑛𝑠 𝑜𝑛 𝑝𝑟𝑖𝑚𝑎𝑟𝑦, 𝑛 𝑝 𝑛𝑢𝑚𝑏𝑒𝑟𝑠 𝑜𝑓 𝑡𝑢𝑟𝑛𝑠 𝑜𝑛 𝑠𝑒𝑐𝑜𝑛𝑑𝑎𝑟𝑦, 𝑛 𝑠
If the transformer is 100% efficient:
𝑝𝑜𝑤𝑒𝑟 𝑠𝑢𝑝𝑝𝑙𝑖𝑒𝑑 𝑡𝑜 𝑡ℎ𝑒 𝑡𝑟𝑎𝑛𝑠𝑓𝑜𝑟𝑚𝑒𝑟=𝑝𝑜𝑤𝑒𝑟 𝑑𝑒𝑙𝑖𝑣𝑒𝑟𝑒𝑑 𝑏𝑦 𝑡ℎ𝑒 𝑡𝑟𝑎𝑛𝑠𝑓𝑜𝑟𝑚𝑒𝑟
𝑝𝑟𝑖𝑚𝑎𝑟𝑦 𝑝𝑑 ×𝑝𝑟𝑖𝑚𝑎𝑟𝑦 𝑐𝑢𝑟𝑟𝑒𝑛𝑡=𝑠𝑒𝑐𝑜𝑛𝑑𝑎𝑟𝑦 𝑝𝑑 ×𝑠𝑒𝑐𝑜𝑛𝑑𝑎𝑟𝑦 𝑐𝑢𝑟𝑟𝑒𝑛𝑡
𝑉 𝑃 × 𝐼 𝑃 = 𝑉 𝑆 × 𝐼 𝑆
KEY WORDS:
South pole
Induction
North pole
Transformer
Magnetic pole
National grid
Magnetic field lines
Step-up transformer
Motor effect
Step-down transformer
‘Split-ring’ commutator
ASSESSMENT: