CIE A Level Physics复习笔记5.1.4 Power
Defining Power The power of a machine is the rate at which it transfers energy Since work done is equal to the energy transferred, power can also be defined as the rate of doing work or the work do...
CIE A Level Physics复习笔记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复习笔记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复习笔记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复习笔记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复习笔记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复习笔记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复习笔记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复习笔记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...
