Definitions

• Physical quantity: Quantity that can be measured, consists of a numerical magnitude and a unit
• Oscillation: Complete to and fro motion of a pendulum
• Period (pendulum): Time taken for one complete oscillation
• Scaler quantities: physical quantities with only magnitude
• Vector quantities: physical quantities with both magnitude and direction
• Speed: Distance moved per unit time
• Velocity: Rate of change of displacement
• Acceleration: rate of change of velocity
• Uniform acceleration: Constant rate of change of velocity
• Mass: amount of matter in a body
• Weight: gravitational force acting on an object with mass
• Gravitational field: Region where a mass experiences a force due to gravitational attraction
• Gravitational field strength: Gravitational force per unit mass placed at that point
• Newtons first law of motion: Every object will continue its state of rest or uniform motion unless a resultant force acts on it
• Inertia: Reluctance of an object to change its state of rest or motion due to its mass
• Newton's second law of motion: When a resultant force acts on a object of constant mass, object will accelerate in the direction of the resultant force
• Newton's third law of motion: If body A exerts a force, F on body B, body B will exert an equal and opposit force Fo on body A
• Termial velocity: Occurs when air resistance acting against the object is equal to its weight, it travels at constant speed with zero acceleration
• Moment of a force: Product of a force and the perpendicular distance from the pivot to the line of action of the force
• Principle of moments: When a body is in equilibrium, sum of clockwise motion about a pivot = sum of anticlockwise motion about the same pivot
• Center of gravity: An imaginary point on a object where the entire weight of the object seems to act
• Stability: Measure of an object's ability to return to its original position
• Pressure: Force acting per unit area
• Pascal's law: If pressure is applied to an enclosed liquid, the pressure is transmitted to all parts of the liquid undiminished
• Density: Mass per unit volume
• Principle of the conservation of energy: Energy cannot be created or destroyed. Energy can be transferred from one store to another. Total energy of a isolated system is constant
• Work done: Product of the force and the distance moved by the object in the direction of the force
• Power: Work done or energy transferred per unit time
• Kinetic particle model of matter: Made up of tiny particles that are in continuous motion
• Thermal equilibrium: State where two or more objects have the same temperature and there is no net transfer of energy between them
• Conduction: Process where energy is transferred through the passing on of vibrational motion from one particle to another
• Convection: Process of energy transfer by means of convection currents in a liquid or gas due to difference in density
• Radiation: Process of energy transfer by electromagnetic waves that does not require a medium
• Internal energy: Total kinetic energy from the random motion of particles and total potential energy between particles in a system
• Heat capacity: Change in internal energy per unit change in temperature
• Specific heat capacity: Change of internal energy per unit mass for each unit change in temperature
• Latent heat: energy released or absorbed to change the state of a substance at a constant temperature
• Latent heat of fusion: Amount of energy transferred to change subtance between solid and liquid states at a constant temperature
• Specific latent heat of fusion: Amount of energy transferred per unit mass to change a substance between solid and liquid state at constant temperature
• Latent heat of vaporisation: Amount of energy transferred to change substance between liquid and gaseous state at constant temperature