sci(physics) definition list

sci(physics) definitions Topic 1 Units & Measurements period (T) time taken for one complete oscillation scalar physical quantity with magnitude and no direction vector physical quantity with magnitude and direction Topic 2 Kinematics distance (scalar) total length of travel by a moving object displacement (vector) measure of change in position of an object speed (scalar) distance travelled per unit time velocity (vector) rate of change of displacement acceleration (vector) rate of change of velocity free fall constant weight falling without air resistance Topic 3 Force & Pressure forces push or pull acting on an object mass (scalar) measure of the amount of matter in a body weight (vector) gravitational force acting on a body gravitational force a region in which a mass experiences a force due to gravitational attraction gravitational field strength gravitational force per unit mass at that point density mass of substance in a unit volume pressure force acting per unit area Topic 4 Dynamics Newton’s Laws (only need to know how to apply) N1L an object will continue its state of rest or stay in motion at uniform velocity unless a resultant force acts on it N2L when an object of constant mass experiences a resultant force, it will accelerate in its direction . the product of the mass and acceleration of the object is equal to the resultant force . (F resultant =ma) N3L every action has an equal & opposite reaction , where the forces act on mutually opposite bodies (action reaction pair) Friction force that slows down or stops the movement of one surface against another page 1 || @javierererie

sci(physics) definitions Topic 5 Turning Effects of Forces moment of a force the product of the force and the perpendicular distance from the pivot to the line of action of force principle of moments for a body at equilibrium , the sum of clockwise moments about a pivot is equal to the sum of anti clockwise moments about the same pivot centre of gravity imaginary point at which the entire weight of the object acts on stability ability of a body to restore to its original position after being displaced Topic 6 Energy work done product of the force & the distance moved in the direction of the force energy the ability to do work kinetic store (ke) the energy an object has due to its motion gravitational potential store (gpe) the energy a body possesses because of its position relative to the ground principle of conservation of energy energy cannot be created or destroyed , but only changes from one form to another . total energy is constant (not considering dissipative forces) power rate of work done / energy conversion Topic 7 Kinetic Particle Model of Matter internal energy sum of kinetic energy and potential energy heat transfer of thermal energy from a body of higher temperature to another of lower temperature temperature measure of degree of hotness or coldness of a body, indicated by the average kinetic energy of its molecules Topic 8 Thermal Properties of Matter thermal equilibrium heat flows from a region of higher temperature to a region of lower temperature until both are at the same temperature conduction the process by which heat is transferred through a medium from one particle to another convection the process by which heat is transmitted from one place to another by movement of heated particles in a gas/liquid due to a difference in density radiation the transfer of thermal energy in the form of electromagnetic waves such as infrared radiation without the aid of a medium page 2 || @javierererie

sci(physics) definitions Topic 9 General Wave Properties waves energy transferred by means of vibrations without the transfer of medium transverse waves (TW) particles travel perpendicular to to the direction of vibration of wave particles longitudinal waves (LW) particles travel parallel to the direction of vibration of wave particles amplitude maximum displacement from rest position crest highest point of transverse wave trough lowest point of transverse wave wavelength (lambda, λ ) distance between 2 successive crests and troughs (TW) or successive compressions and rarefactions (LW) period (T) time taken for one complete wave frequency (f) number of waves generated in one second wave speed (v) distance moved by wave in one second wavefront imaginary line connecting adjacent points in the same phase of vibrations sound a form of energy produced by the vibration of objects placed in a medium Topic 11 Light laws of reflection incident ray, reflected ray, and normal all lie on the same plane angle of incidence = angle of reflection refraction the bending effect of light as it passes from one optical medium to another due to change in speed laws of refraction incident ray, reflected ray, and normal all lie on the same plane for any two particular media , the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant (n = sin i / sin r) refractive index the ratio of the speed of light in vacuum to the speed of light in the medium focal point point where parallel light rays meet after passing through lens and coming to a focus focal length distance between optical centre and principal focus page 3 || @javierererie

sci(physics) definitions Topic 12 Electric Charge & Current of Electricity current rate of flow of electric charges through a given cross-section of a conductor electromotive force (emf) the work done by the source in driving a unit charge around a complete circuit potential difference (pd) the work done per unit charge in driving charges through a component resistance the ratio of the potential difference across it to the current flowing through it ( ) 𝑅 = 𝑉 𝐼 resistivity property of a material, independent of dimensions Topic 15 Magnetism & Electromagnetism magnetic field region around a magnet in which a magnetic force can be detected induced magnetism magnetic materials are magnetised when near or in contact with a permanent magnet the motor effect when current carrying conductor is placed in a magnetic field, it experiences a force (FLHR) Topic 16 Radioactivity nuclear decay spontaneous and random process that occurs when an unstable nucleus transitions into a more stable state by emitting radiation random cannot know which nucleus will decay spontaneous cannot know when nucleus decay will occur half life time taken for half the number of nuclei to decay background radiation standard radiation levels in the environment page 4 || @javierererie