OCR A level Physics: Gravitational Fields is apart of the Module 5: Newtonian world and Astrophysics. All presentations come with worked examples, solutions and homeworks. 18.1 Gravitational Fields 18.2 Newton’s law of gravitation 18.3 Gravitational field strength for a point mass 18.4 Kepler’s laws 18.5 Satellites 18.6 Gravitational potential 18.7 Gravitational potential energy The terms: eccentricity, aphelion, perihelion, astronomical unit Kepler’s First Law Kepler’s Second Law Kepler’s Third Law Graphs of T^2 against r^3 to determine the gradient (constant of proportionality, k). Equating (4π)^2/𝐺𝑀 to the gradient (constant of proportionality, k) Key features of geostationary and low polar orbit satellites Conditions for stable orbits for satellites Applying Kepler’s laws to the orbits of satellites Radial and uniformed field Definition of gravitational potential energy Deriving escape velocity Force-Distance graphs for gravitational fields Center of mass and treating spherical objects as point masses Gravitational fields Definition of gravitational potential Applying the gravitational potential equation Graph of gravitational potential against distance (V against r) Combining gravitational potentials from more than one mass

OCR AS level Chemistry: Haloalkanes is apart of the Module 4: Core Organic Chemistry and Analysis All presentations come with worked examples, solutions and homeworks Naming Haloalkanes Classifying Haloalkanes (primary, secondary, tertiary) Electronegativity Reaction mechanism for hydrolysis Rates of reactions for hydrolysis Reaction conditions for hydrolysis Definitions for CFC (Chlorofluorocarbons) and HCFC (Hydachlorofluorocarbons) Creation of ozone Depletion of ozone with CFCs Reaction steps including initiations and propagation