Definition (physics).docx

Chapter 1 Physical quantities – the quantities that are measurable with instruments in laboratory or can be derived from the measured quantities Basic quantities – the quantities that cannot be derived in terms of other physical quantities Derived quantities – the physical quantities that are derived from other basic quantities according to a difining equation Dimension – is a method used to describe a physical quantities in term of its basic quantities regardless the system of units used Scalar quantities – quantity with magnitude only Vector quantities – quantity with both magnitude and direction

Chapter 2 Kinematic – description of motion of object without consideration of what causes the motion (mass of force) Linear motion – the motion of an object along a straight line path Distance – the total length of the travel in moving from one location to another Displacement – the shortest distance from the initial position to the final position of an object Speed – the distance travelled per unit time Average speed – the total distance travelled divided by the total time elapsed Velocity – Average velocity – the rate change of displacement Instantaneous velocity – velocity at a specific position or instant of time along the path of motion Acceleration – rate change of velocity Average acceleration – change in velocity divided by the time taken to make the change Instantaneous acceleration – the acceleration at a particular instant of time

Chapter 3 Linear momentum – product of mass and velocity Impulse – the change of momentum / the product of force and time Principle of conservation of linear momentum – in an isolated system, the total momentum of the system is constant

Chapter 4 Weight – force acting on it due to the gravitational pull Normal Reaction force – the force that exists whenever 2 solid surface are in contact Tension – the force in a cord that pulls on a body Friction – the force that resists the motion of a body as it slides over the rough surface Newton 1st Law of Motion – states if there is no net force acting on the object, the object at rest will remains at rest, or continue to move with uniform velocity in a straight line Newton 2nd Law of Motion – states the rate change of momentum of a moving body is directly proportional to the resultant force and is in the same direction as the force acting on it Newton 3rd Law of Motion – every action force has a reaction that is equal in magnitude but opposite in the direction

Chapter 5 Work – the product of the magnitude of the displacement times the component of the force parallel to the displacement Kinetic energy – energy of a body due to its motion Potential energy – energy stored in a body or a system because of its position, shapes and the state Gravitational potential energy – Energy stored in a body or a system because of its position Elastic potential energy – energy stored in elastic materials as the result of their stretching or compressing Conservation of Mechanical Energy – in a conservative system, the total mechanical energy is constant Power – the rate at which work is done

Chapter 6 Circular Motion – motion which occurs when bodies rotate around something or move in a circular path Angular displacement – the angle undergone by an object from a fixed reference point Angular velocity – the rate change of angular displacement Period – time for an object to make one complete revolution Centripetal acceleration – the acceleration of an object moving in circular path whose direction is towards the centre of the circular path Centripetal force – the net force required to keep an object of mass m, moving at a speed v on a circular path or radius r

Chapter 7 Gravitational force – the force which one body attract the others due to their mass Newton’s Law of Gravitation – 2 bodies attract each other with a force which is directly proportional to the product of their mass and inversely proportional to the square of the distance between their centre. Gravitational Field – the region where a body having a mass experience gravitational force Gravitational Field Strength – gravitational force per unit mass acting on a body at that point Gravitational potential energy – the work done by a gravitational force in bringing a test mass from infinity to a point

Chapter 9 Simple Harmonic Motion – the motion of an object without the loss of energy where its acceleration is directly proportional to the displacement from equilibrium point and in opposite direction Equilibrium position – a point where the acceleration of the body undergoing oscillation is zero Restoring Force – the force which cause simple harmonic motion to occur

Chapter 10 Progressive Wave – wave that propagates continuously outward from the source of disturbance Particle displacement – the displacement of a particle from its equilibrium position Wave displacement – the displacement of a particle from the source of the disturbance Amplitude – the maximum distance from the particle equilibrium position Frequency – the number of complete waveforms that pass by a given point during each second Period – the time for one complete waveforms to pass by a given point Wavelength – the distance between two successive crest or trough Standing wave – the wave whose profile doesn’t advance and no energy is transferred from 1 end of the medium to another end Intensity – the energy transported per unit time across a unit area which is perpendicular to the direction of the wave propagation Doppler effect – the change in the frequency of the sound when there is a relative motion between the source of the sound and the observer *the progressive wave is produced by the source of disturbance, meanwhile the standing wave is produced by the superposition of two identical progressive waves travel in opposite direction

Chapter 11 Stress – the forcing acting per unit cross sectional area Strain – the elongation per unit length Young Modulus – ratio of tensile stress to strain

Chapter 12 Temperature – relative measurement of hotness or coldness Heat – the energy transferred from one object to another because of the difference in the temperature between the two object Heat conduction – process where the heat is transferred through a solid from the region of high temperature to low temperature Heat conductivity – the characteristic of heat conducting ability of a material

Chapter 13 Boyle’s Law – for a fixed amount of gas at a constant temperature, gas pressure is inversely proportional to the gas volume Charles’s Law – for a fixed amount of gas at a constant pressure, gas volume is directly proportional to its absolute temperature Pressure Law – for a fixed amount of gas at a constant temperature, the gas pressure is directly proportional to its absolute temperature Gas pressure – the result of the collision of the large amount of molecules on the wall of container Principle of Equipartition of Energy – the mean kinetic energy associated with each degree of freedom of a molecule is ½kT Assumption of Kinetic Theory of Gases: -

All gases are made of atoms or molecules All atoms or molecules move randomly The volume of the atoms/molecules is negligible when compared with the volume occupied by the gas The molecules undergo perfectly elastic collision with each other & the wall of container The intermolecular force are negligible except during collision The time of collision between molecules is negligible compared to the time between collision Atoms/molecules move with constant velocity between collision. Gravity has no effect on molecular motion

Chapter 14 First Law of Thermodynamic – The heat supplied to the system is equal to the increase of internal energy of the system plus work done by the system on the surroundings