CIE A Level Physics復習筆記5.1.3 Efficiency
Efficiency of a System The efficiency of a system is?the ratio of the useful energy output from the system to the total energy input If a system has?high?efficiency, this means most of the energy t...
CIE A Level Physics復習筆記5.1.2 The Principle of Conservation of Energy
The Principle of Conservation of Energy The Principle of Conservation of Energy states that: Energy cannot be created or destroyed, it can only change from one form to another This means the total ...
CIE A Level Physics復習筆記5.1.1 Work & Energy
Work Done In Physics,?work is done?when an?object?is?moved?over a distance by an external force applied in the direction of its displacement In the diagram below, the man’s pushing force on the blo...
CIE A Level Physics復習筆記4.2.5 Archimedes Principle
Archimedes' Principle Archimedes’ principle states that an object submerged in a fluid at rest has?an upward buoyancy force (upthrust) equal to the weight of the fluid displaced by the object The o...
CIE A Level Physics復習筆記4.2.4 Upthrust
Upthrust Upthrust is a force which pushes upwards on an object submerged in a fluid i.e. liquids and gases Also known as buoyancy force, upthrust is due to the?difference in hydrostatic pressure?at...
CIE A Level Physics復習筆記4.2.3 Derivation of ?p = ρg?h
Derivation of ?p = ρg?h Hydrostatic pressure?is the pressure that is exerted by a?fluid?at equilibrium at a given point within the fluid, due to the force of gravity The derivation for this equatio...
CIE A Level Physics復習筆記4.2.2 Pressure
Pressure Pressure tells us how concentrated a force is, it is defined as the?force per unit area Pressure is equal to the force per unit area This equation tells us If a force is spread over a larg...
CIE A Level Physics復習筆記4.2.1 Density
Density Density is the?mass per unit volume?of an object Objects made from low-density materials typically have a lower mass For example, a balloon is less dense than a small bar of lead despite oc...
CIE A Level Physics復習筆記4.1.4 Conditions for Equilibrium
Equilibrium A system is in equilibrium when all the forces are balanced. This means: There is?no?resultant force There is?no?resultant torque An object in equilibrium will therefore remain at rest,...
CIE A Level Physics復習筆記4.1.3 Turning Effects of Forces
Couples A couple is a?pair?of forces that acts to produce?rotation?only Unlike moments of a single force, the moment of a couple doesn’t depend on a pivot, only on the perpendicular distance betwee...
CIE A Level Physics復習筆記4.1.2 Moments
What is a Moment? A moment is the?turning effect of a force Moments occur when forces cause objects to?rotate?about some pivot The moment of a force is given by Moment (N m) = Force (N) × perpendic...
CIE A Level Physics復習筆記4.1.1 Centre of Gravity
Centre of Gravity The centre of gravity of an object is?the point at which the weight of the object may be considered to act For example, for a person standing upright, their centre of gravity is r...
