Modelling Assumptions What is modelling in Mechanics? Mechanics uses modelling to solve problems in real life situations We use assumptions to simplify real life problems in order to turn them into...
Types of Force What is a force? A force is a vector quantity, it has both magnitude and direction A force is a push or a pull on an object A force is measured in Newtons In A level mathematical mod...
Derived Units What are derived units? Derived units for quantities such as velocity, acceleration and force etc. are combinations of S.I. units Speed or Velocity = distance ÷ time = m/s or m s-1 (V...
Fundamental Units What are fundamental units? Fundamental units or S.I. units are the international standardised units used around the world The three main units you will be using are: Length measu...
Scalars & Vectors Mechanics uses a variety of different scalar and vector quantities. What are scalars? Scalars are quantities without direction, they only have a size (magnitude) e.g. a speed ...
Hubble's Law & the Big Bang Theory Edwin Hubble investigated the light spectra emitted from a large number of galaxies He used redshift data to determine the recession velocities of these galax...
Redshift of EM Radiation Recall the Doppler effect is defined as: The apparent change in wavelength or frequency of the radiation from a source due to its relative motion away from or toward the ob...
Emission Spectra Astronomers are very limited in how they can investigate objects in the space All of the techniques used involve analysing the light emitted from the star, or galaxy One of these t...
Stefan-Boltzmann Law A star’s luminosity depends on two factors: Its surface temperature Its radius The relationship between these is known as the Stefan-Boltzmann Law, which states: The total ener...
