0. H2.Physics.Definition_List.2023 20230301

CJC Definition List 2023 1 | P a g e CATHOLIC JUNIOR COLLEGE 9749 H2 PHYSICS DEFINITION LIST Measurements Forces Dynamics Kinematics Work, Energy and Power Motion in a Circle Gravitational Field Oscillations Waves Superposition Thermal Physics Electric Field Current of Electricity / D.C. Circuits Alternating Current Electromagnetism and Electromagnetic Induction Quantum Physics Nuclear Physics

CJC Definition List 2023 2 | P a g e Measurements Random Error: is an error which gives a scatter of readings about an average value. It has an equal chance of being positive or negative and can be reduced by averaging. Systematic Error: is a constant deviation of readings in one direction. All measurements will be too high or too low by a certain amount . It can be reduced by correct laboratory practice. Precision (of a set of readings): Precision (of an instrument) is the degree of closeness of the readings with one another. It is associated with small random error. a term used to describe the level of uncertainty in an instrument’s scale. High precision instruments have small scale divisions. Accuracy (of a set of readings): Accuracy (of an instrument): is the degree of closeness of the average value of the readings to the true value. It is associated with small systematic error. is the closeness of a reading on an instrument to the true value of the quantity being measured. An accurate instrument will give readings close to the true values. N22/II/Q2ai[1] Vector Quantity: is a quantity having both magnitude and direction. Scalar Quantity: is a quantity that has magnitude only, not direction. Kinematics Distance: is the total length of the actual path travelled by an object in motion. It is a scalar quantity. Displacement: is the straight l ine distance of an object or a point, in a specified direction, from some reference point. The specified direction is directed from the reference point to that object’s position or that point. Displacement is a vector quantity. Speed: is the rate of change of distance with respect to time. Velocity: is the rate of change of displacement with respect to time. N15/III/6ai [1] Acceleration: is the rate of change of velocity with respect to time.

CJC Definition List 2023 3 | P a g e Dynamics Newton's First Law of Motion: A body stays at rest or continues to move at constant velocity unless a resultant force acts on it. N10/II/1a [1] Newton's Second Law of Motion: the rate of change of momentum of a body is directly proportional to the net force acting on it, and , the direction of momentum change is in the direction of the net force. Newton's Third Law of Motion: Whenever a force acts on a body, an equal but oppositely directed force of the same kind acts on another body. Characteristic of Action-Reaction Pair: The action-reaction pair forces • are of the same nature