Methods of Heat Transfer - Conduction, Convection and Radiation
The three methods of heat transfer are conduction, convection and radiation. Whatever the method, heat always travels from hot to cold. Conduction Conduction is the main heat transfer process in solids, much less so in liquids and gases. It is a slow...
https://astarmathsandphysics.com/igcse-physics-notes/382-methods-of-heat-transfer-conduction-convection-and-radiation.htmlThe Danger From Mobile Phone Masts
Every time a call is made or received on a mobile phone, the phone is connected to the aerial for the local cell. The aerial then connects to other aerials until eventually contact is made with the phone at the other end of the call. Aerials radiate...
https://astarmathsandphysics.com/gcse-physics-notes/837-the-danger-from-mobile-phone-masts.htmlFinding a Generating Function From a Given Canonical Transformation
Generating functions have many uses and it is useful to be able to construct one from a given transformation. We can do this from the defining relationship between the generating function and the transformation. Example Show that the transformation is...
https://astarmathsandphysics.com/university-physics-notes/classical-mechanics/1520-finding-a-generating-function-from-a-given-canonical-transformation.htmlLeast Distance of Line From Origin
The line of least distance between a given line and the origin is perpendicular to that line. Since the line of least distance passes through the origin, we can find the equation of this line, then by solving simultaneous equations, the point of...
https://astarmathsandphysics.com/a-level-maths-notes/c1/5025-least-distance-of-line-from-origin.htmlThe Suns Corona
TheSuns corona is the gas consisting of hot ionized gas or plasma surrounding the Sun, extending millions of km into space. It is normally made invisible by the Suns glare, but is clearly visible during a solar eclipse. The temperature of the corona is...
https://astarmathsandphysics.com/university-physics-notes/astronomy/1516-the-suns-corona.htmlFinding the Mode, Median and Mean From Frequency Tables
Suppose we start from a frequency table of lengths versus frequencies. Length Frequency 0-10 2 10-20 16 20-30 46 30-40 35 40-50 7 Finding the Mode The mode is just the most common length interval, with the highest frequency: 20-30. To find the median...
https://astarmathsandphysics.com/o-level-maths-notes/334-finding-the-mode-median-and-mean-from-frequency-tables.htmlReflection From a Potential Barrier
When a particle represented by a wavefunction hits a potential barrier, it is not automatically relected, even if it has insufficient energy to over come the barrier according to classical mechanics. If the potential barrier has finite height, the...
https://astarmathsandphysics.com/university-physics-notes/quantum-mechanics/1639-reflection-from-a-potential-barrier.htmlQuartiles & Median From Frequency Tables
We start with the table below which summarises the daily sales in a newspaper shop over a year for the 360 days the shop was open. Sales Number of Days 1 -200 166 201- 400 100 401 - 700 59 701 - 1000 30 1001 -1500 3 To find the lower quartile we use...
https://astarmathsandphysics.com/ib-maths-notes/probability-and-statistics/1063-quartiles-and-median-from-frequency-tables.htmlEquation of Hyperbola From Asymptotes and Point on Curve
A hyperbola has asymptotes \[x=\frac{3}{2}, \: y=4\] and passes through the point \[(2,1)\] . How can we find the equation of the asymptote? The equation of a hyperbola can be written in the form \[(x-x_0)(y-y_0)=k\] where \[x=x_0, \: y=y_0\] are the...
https://astarmathsandphysics.com/ib-maths-notes/functions/5014-equation-of-hyperbola-from-asymptotes-and-point-on-curve.htmlFinding the Equation of a Plane from Three Points
A line, which is a two dimensional object, is fixed by two points on it – two dimensions, two points. The equation of a line can be written given by – this is the cartesian form of the line. The cartesian form of a plane is where and are constants To...
https://astarmathsandphysics.com/ib-maths-notes/vectors-lines-and-planes/1157-finding-the-equation-of-a-plane-from-three-points.htmlThe Domestic Hot Water Supply
The domestic hot water supply system consists of a boiler, a hot water storage tank and a cold water supply tank interconnected by pipes arranged as below left. A convection current of hot water from the boiler rises up the flow pipe A while cold water...
https://astarmathsandphysics.com/o-level-physics-notes/237-the-domestic-hot-water-supply.htmlMass Defect and Binding Energy
The mass of a nucleus is never quite equal to the sums of the masses of the constituent nucleons (protons and neutrons). It is a little bit more or a little bit less. The difference between the mass of a nucleus and the sum of the masses of the...
https://astarmathsandphysics.com/ib-physics-notes/atomic-and-nuclear-physics/1221-mass-defect-and-binding-energy.htmlThe Photoelectric Effect - Finding Planck's Constant
When light is shone on a metal surface, electrons may be emitted from the surface. Sometimes electrons are emitted, sometimes not. It depends on the energy, hence the frequency, of the incident light. In the diagram, light enters from the top left. It...
https://astarmathsandphysics.com/ib-physics-notes/quantum-and-nuclear-physics/1434-the-photoelectric-effect-finding-planck-s-constant.htmlMorphisms
A morphism is a mapping between sets. The different types of morphism are Homomorphism: preserves the structure (e.g. ) where and are the operations on the domain and codomain respectively. For example exp is a morphism from to where is the set of...
https://astarmathsandphysics.com/university-maths-notes/abstract-algebra-and-group-theory/1701-morphisms.htmlSampling Methods
Gathering statistics involves time and effort. It is a necessary procedure – governments need to know how many schools to build, or policemen to employ, and companies need to know which products people will buy. They could go out and ask everyone, but...
https://astarmathsandphysics.com/gcse-maths-notes/645-sampling-methods.htmlHubble's Law
When we look at the spectra from distant galaxies, we find that the light from them is shifted towards the red end of the spectrum. The wavelength of the light we receive is longer than the wavelength of light due to the same atomic transitions on...
https://astarmathsandphysics.com/ib-physics-notes/astrophysics/1193-hubble-s-law.htmlRadiation Effects and Safety
At the molecular level, radiation can cause ionisation in tissue, damaging biological molecules. The strands of DNA are held together by hydrogen bonds, which are very weak and easily broken. Ionisation in the surrounding medium – the cytoplasm in the...
https://astarmathsandphysics.com/ib-physics-notes/biomedical-physics/1250-radiation-effects-and-safety.htmlThe Heliosphere and the Boundary of the Solar System
The heliosphere is that part of space dominated by the Sun and is filled with charged particles streaming off the Sun – the 'Solar Wind'. For the first ten billion km of its journey from the Sun the solar wind travels at over 1,000,000 km/h. As it...
https://astarmathsandphysics.com/university-physics-notes/astronomy/1510-the-heliosphere-and-the-boundary-of-the-solar-system.htmlWater Waves on a Sloping Beach
To the landperson waves are most encountered at the beach, or swimming near the beach. Far from the beach the waves are nearly uniform progressive waves with wavelength from a few metres to a few hundred metres and speeds ranging from 4m/s to 20m/s....
https://astarmathsandphysics.com/university-physics-notes/fluid-mechanics/1584-water-waves-on-a-sloping-beach.htmlConstructing an Angle of 45 Degrees
give an angle of 45°. Putthe compass point at A and draw an arc which crosses the other twosides of the triangle. From where the arccrosses the sides of the triangle, without altering the compasslength, draw extra arcs. Draw a line fromthe right angle...
https://astarmathsandphysics.com/igcse-maths-notes/457-constructing-an-angle-of-45-degrees.html