AQA GCSE Physics Correctly Answered 100%

AQA GCSE Physics Correctly Answered 100% Vectors Quantities that have a magnitude and direction Scalars Quantities that only have a magnitude Vector Examples Force, velocity, displacement, acceleration, momentum Scalar Examples Speed, distance, mass, temperature, time Contact Forces A force that requires 2 objects to be touching Non-Contact Forces A force that does not require 2 objects to be touching Contact Force Examples Friction, air resistance, tension Non-Contact Force Examples Magnetism, gravity, electrostatic forces Weight The force acting on an object due to gravity Mass The amount of 'stuff' in an object Weight Equation Weight (N) = Mass (kg) x Gravitational Field Strength (N/kg) Earth's Gravitational Field Strength 9.8N/kg Resultant Force The overall force on a point or object Extension Equation Force (N) = Spring Constant (N/m) x Extension (m) Moment Equation Moment (Nm) = Force (N) x Distance (m) Moment The turning effect of a force Pressure Equation Pressure (Pa) = Force (N) / Area (m) Pressure Of A Liquid Equation Pressure (Pa) = Height (m) x Density (kg/m) x Field strength (N/kg) Upthrust Force on an object. If it is equal to the object's weight, it will float. If the upthrust is less than the weight, it will sink Floating Depends on the density of the solid compared to the density of the liquid Atmospheric Pressure Created on a surface by air molecules. Decreases with height Distance How far an object has moved. It is a scalar quantity Displacement Vector quantity. Measures distance and direction in a straight line from A to B Walking Speed 1.5m/s Running Speed 3m/s Cycling Speed 6m/s Car Speed 25m/s Train Speed 55m/s Plane Speed 250m/s Acceleration Equation Acceleration (m/s) = Change in velocity (m/s) / Time (s) Uniform Acceleration Equation 2 x Acceleration x Distance = Final velocity^2 - Initial velocity^2 Distance Time Graph Gradient Tells you the speed Velocity Time Graph Gradient Tells you the acceleration Friction Force between 2 surfaces in contact. Acts in the opposite direction to movement Drag Resistance in air or fluid Terminal Velocity The fastest speed that an object can travel. Happens when friction and acceleration forces are equal Newton's First Law If the resultant force on a stationary object is zero, the object will remain stationary. If the resultant force on a moving object is zero, it'll carry on moving at the same velocity Newton's Second Law Acceleration is proportional to the resultant force Resultant Force Equation Resultant Force (N) = Mass (kg) x Acceleration (m/s) Newton's Third Law When two objects interact, the forces they exert on each other are equal and opposite Inertia The tendency for motion to remain unchanged Stopping Distance Equation Stopping Distance = Thinking Distance + Breaking Distance Thinking Distance Factors Speed, reaction time, alcohol, drugs Breaking Distance Factors Speed, weather, tyre condition, brake quality 30mph Distances Thinking = 9m, Breaking = 14m 50mph Distances Thinking = 15m, Breaking = 38m 70mph Thinking = 21m, Breaking = 75m Momentum Equation Momentum (kg m/s) = Mass (kg) x Velocity (m/s) Momentum How much 'oomph' an object has. In a close system it is always conserved Change In Momentum Equation Force (N) = Change in momentum (kg m/s) / Change in time (s) Crumple Zone Area on a car designed to crumple, increasing the time it takes the car to stop Seat Belts Stretchy meaning that it takes longer for the wearer to stop in the event of an accident Air Bags Initiate before you hit the dashboard of a car. Slows you down gradually